diff --git a/.travis.yml b/.travis.yml
index cc4d3cf..eb3f49a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,5 +14,5 @@ script:
   - phpize
   - ./configure
   - make
-  - make test
+  - echo $'n\n' | make test
   - sudo make install
\ No newline at end of file
diff --git a/src/collections_methods.c b/src/collections_methods.c
index 2bed811..25f0b74 100644
--- a/src/collections_methods.c
+++ b/src/collections_methods.c
@@ -9,22 +9,30 @@
 #include "php_collections.h"
 #include "php_collections_me.h"
 
-#define NEW_COLLECTION_OBJ(name) \
+#define NEW_OBJ(name, ce) \
     zend_object* (name) = (zend_object*)ecalloc(1, sizeof(zend_object) + \
-    zend_object_properties_size(collections_collection_ce)); \
-    zend_object_std_init(name, collections_collection_ce); \
-    object_properties_init(name, collections_collection_ce); \
-    obj->handlers = &std_object_handlers;
+    zend_object_properties_size(ce)); \
+    zend_object_std_init(name, ce); \
+    object_properties_init(name, ce); \
+    (name)->handlers = &std_object_handlers;
+#define NEW_COLLECTION_OBJ(name) NEW_OBJ(name, collections_collection_ce)
+#define NEW_PAIR_OBJ(name) NEW_OBJ(name, collections_pair_ce)
 
 #define IS_COLLECTION(zval) \
     Z_TYPE_P(elements) == IS_OBJECT && Z_OBJCE_P(elements) == collections_collection_ce
 
-#define COLLECTION_UPDATE(obj, value) \
-    zend_update_property_ex(zend_get_executed_scope(), obj, collection_property_name, value)
+#define OBJ_PROPERTY_UPDATE(obj, property_name, value) \
+    zend_update_property_ex(zend_get_executed_scope(), obj, property_name, value)
+#define OBJ_PROPERTY_FETCH(obj, property_name) \
+    zend_read_property_ex(zend_get_executed_scope(), obj, property_name, 1, &rv)
+#define COLLECTION_UPDATE(obj, value) OBJ_PROPERTY_UPDATE(obj, collection_property_name, value)
 #define COLLECTION_UPDATE_EX(value) COLLECTION_UPDATE(getThis(), value)
-#define COLLECTION_FETCH(obj) \
-    zend_read_property_ex(zend_get_executed_scope(), obj, collection_property_name, 1, &rv)
+#define COLLECTION_FETCH(obj) OBJ_PROPERTY_FETCH(obj, collection_property_name)
 #define COLLECTION_FETCH_EX() COLLECTION_FETCH(getThis())
+#define PAIR_UPDATE_FIRST(obj, value) OBJ_PROPERTY_UPDATE(obj, pair_first_name, value)
+#define PAIR_UPDATE_SECOND(obj, value) OBJ_PROPERTY_UPDATE(obj, pair_second_name, value)
+#define PAIR_FETCH_FIRST(obj) OBJ_PROPERTY_FETCH(obj, pair_first_name)
+#define PAIR_FETCH_SECOND(obj) OBJ_PROPERTY_FETCH(obj, pair_second_name)
 
 #define PHP_COLLECTIONS_ERROR(type, msg) php_error_docref(NULL, type, msg)
 #define ERR_BAD_ARGUMENT_TYPE() PHP_COLLECTIONS_ERROR(E_WARNING, "Bad argument type")
@@ -78,8 +86,8 @@ PHP_METHOD(Collection, all)
     ZEND_PARSE_PARAMETERS_START(1, 1)
         Z_PARAM_FUNC(fci, fcc)
     ZEND_PARSE_PARAMETERS_END();
-    zval params[3], rv, retval;
-    fci.param_count = 3;
+    zval params[2], rv, retval;
+    fci.param_count = 2;
     fci.retval = &retval;
     fci.params = params;
     zval* current = COLLECTION_FETCH_EX();
@@ -88,8 +96,7 @@ PHP_METHOD(Collection, all)
         if (bucket->key)
             ZVAL_STR(&params[1], bucket->key);
         else
-            ZVAL_NULL(&params[1]);
-        ZVAL_LONG(&params[2], bucket->h);
+            ZVAL_LONG(&params[1], bucket->h);
         zend_call_function(&fci, &fcc);
         if (Z_TYPE(retval) == IS_FALSE)
             RETURN_FALSE;
@@ -99,7 +106,27 @@ PHP_METHOD(Collection, all)
 
 PHP_METHOD(Collection, any)
 {
-    
+    zend_fcall_info fci;
+    zend_fcall_info_cache fcc;
+    ZEND_PARSE_PARAMETERS_START(1, 1)
+        Z_PARAM_FUNC(fci, fcc)
+        ZEND_PARSE_PARAMETERS_END();
+    zval params[2], rv, retval;
+    fci.param_count = 2;
+    fci.retval = &retval;
+    fci.params = params;
+    zval* current = COLLECTION_FETCH_EX();
+    ZEND_HASH_FOREACH_BUCKET(Z_ARRVAL_P(current), Bucket* bucket)
+        ZVAL_COPY(&params[0], &bucket->val);
+        if (bucket->key)
+            ZVAL_STR(&params[1], bucket->key);
+        else
+            ZVAL_LONG(&params[1], bucket->h);
+        zend_call_function(&fci, &fcc);
+        if (Z_TYPE(retval) == IS_TRUE)
+            RETURN_TRUE;
+    ZEND_HASH_FOREACH_END();
+    RETURN_FALSE;
 }
 
 PHP_METHOD(Collection, associate)
@@ -649,5 +676,12 @@ PHP_METHOD(Collection, values)
 
 PHP_METHOD(Pair, __construct)
 {
-    
+    zval* first;
+    zval* second;
+    ZEND_PARSE_PARAMETERS_START(2, 2)
+        Z_PARAM_ZVAL(first)
+        Z_PARAM_ZVAL(second)
+    ZEND_PARSE_PARAMETERS_END();
+    PAIR_UPDATE_FIRST(getThis(), first);
+    PAIR_UPDATE_SECOND(getThis(), second);
 }
\ No newline at end of file
diff --git a/stubs/Collection.php b/stubs/Collection.php
index d0de4b4..742773c 100644
--- a/stubs/Collection.php
+++ b/stubs/Collection.php
@@ -22,7 +22,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns true if all elements match the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return bool
      */
     function all($predicate) {}
@@ -30,7 +30,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns true if at least one element matches the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return bool
      */
     function any($predicate) {}
@@ -141,7 +141,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a collection containing only elements from the given array having distinct keys
      * returned by the given selector function.
      *
-     * @param callable $selector ($value, $key, $index) -> $key
+     * @param callable $selector ($value, $key) -> $key
      * @return Collection
      */
     function distinctBy($selector) {}
@@ -166,7 +166,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a collection containing all elements except last elements that satisfy
      * the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return Collection
      */
     function dropLastWhile($predicate) {}
@@ -175,7 +175,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a collection containing all elements except first elements that satisfy
      * the given predicate.
      *
-     * @param $predicate $predicate ($value, $key, $index) -> bool
+     * @param $predicate $predicate ($value, $key) -> bool
      * @return Collection
      */
     function dropWhile($predicate) {}
@@ -193,7 +193,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns a collection containing only elements matching the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return Collection
      */
     function filter($predicate) {}
@@ -201,7 +201,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns a collection containing only elements not matching the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return Collection
      */
     function filterNot($predicate) {}
@@ -210,7 +210,7 @@ class Collection implements ArrayAccess, Countable
      * Appends all elements not matching the given predicate to the given destination.
      *
      * @param Collection $destination
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return Collection
      */
     function filterNotTo($destination, $predicate) {}
@@ -219,7 +219,7 @@ class Collection implements ArrayAccess, Countable
      * Appends all elements matching the given predicate to the given destination.
      *
      * @param Collection $destination
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return Collection
      */
     function filterTo($destination, $predicate) {}
@@ -228,7 +228,7 @@ class Collection implements ArrayAccess, Countable
      * Returns the first element matching the given predicate, or null if no such
      * element was found.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return mixed
      */
     function find($predicate) {}
@@ -237,7 +237,7 @@ class Collection implements ArrayAccess, Countable
      * Returns the last element matching the given predicate, or null if no such
      * element was found.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return mixed
      */
     function findLast($predicate) {}
@@ -245,7 +245,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns the first element matching the given predicate.
      *
-     * @param callable $predicate[optional] ($value, $key, $index) -> bool
+     * @param callable $predicate[optional] ($value, $key) -> bool
      * @return mixed
      */
     function first($predicate) {}
@@ -254,7 +254,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a collection of all elements yielded from results of transform function
      * being invoked on each element of original collection.
      *
-     * @param callable $transform ($value, $key, $index) -> array|Collection
+     * @param callable $transform ($value, $key) -> array|Collection
      * @return Collection
      */
     function flatMap($transform) {}
@@ -264,7 +264,7 @@ class Collection implements ArrayAccess, Countable
      * original collection, to the given destination.
      *
      * @param Collection $destination
-     * @param callable $transform ($value, $key, $index) -> array|Collection
+     * @param callable $transform ($value, $key) -> array|Collection
      * @return Collection
      */
     function flatMapTo($destination, $transform) {}
@@ -299,7 +299,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Performs the given action on each element.
      *
-     * @param callable $action ($value, $key, $index) -> void
+     * @param callable $action ($value, $key) -> void
      * @return void
      */
     function forEach($action) {}
@@ -319,7 +319,7 @@ class Collection implements ArrayAccess, Countable
      * original array by the key returned by the given key_selector function applied to the element
      * and returns a collection where each group key is associated with a list of corresponding values.
      *
-     * @param callable $key_selector ($value, $key, $index) -> $new_key
+     * @param callable $key_selector ($value, $key) -> $new_key
      * @param callable $value_transform[optional] ($value) -> $new_value
      * @return Collection
      */
@@ -331,7 +331,7 @@ class Collection implements ArrayAccess, Countable
      * puts to the destination collection each group key associated with a list of corresponding values.
      *
      * @param Collection $destination
-     * @param callable $key_selector ($value, $key, $index) -> $new_key
+     * @param callable $key_selector ($value, $key) -> $new_key
      * @param callable $value_transform[optional] ($value) -> $new_value
      * @return Collection
      */
@@ -366,7 +366,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Initialize collection with given data.
      *
-     * @param array|Collection $elements[$optional]
+     * @param array|Collection $elements[optional]
      * @return Collection
      */
     static function init($elements) {}
@@ -401,7 +401,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns the last element matching the given predicate.
      *
-     * @param callable $predicate[optional] ($value, $key, $index) -> bool
+     * @param callable $predicate[optional] ($value, $key) -> bool
      * @return mixed
      */
     function last($predicate) {}
@@ -418,7 +418,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a collection containing the results of applying the given transform function
      * to each element in the original collection.
      *
-     * @param callable $transform ($value, $key, $index) -> Pair
+     * @param callable $transform ($value, $key) -> Pair
      * @return Collection
      */
     function map($transform) {}
@@ -427,7 +427,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a new collection with entries having the keys obtained by applying the transform function
      * to each keys and values of this collection.
      *
-     * @param callable $transform ($value, $key, $index) -> $new_key
+     * @param callable $transform ($value, $key) -> $new_key
      * @return Collection
      */
     function mapKeys($transform) {}
@@ -437,7 +437,7 @@ class Collection implements ArrayAccess, Countable
      * transform function to each keys and values of this collections.
      *
      * @param Collection $destination
-     * @param callable $transform ($value, $key, $index) -> $new_key
+     * @param callable $transform ($value, $key) -> $new_key
      * @return Collection
      */
     function mapKeysTo($destination, $transform) {}
@@ -447,7 +447,7 @@ class Collection implements ArrayAccess, Countable
      * results to the given destination.
      *
      * @param Collection $destination
-     * @param callable $transform ($value, $key, $index) -> Pair
+     * @param callable $transform ($value, $key) -> Pair
      * @return Collection
      */
     function mapTo($destination, $transform) {}
@@ -456,7 +456,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a new collection with entries having the keys of this collection and the values obtained
      * by applying the transform function to each entry in this collection.
      *
-     * @param callable $transform ($value, $key, $index) -> $new_value
+     * @param callable $transform ($value, $key) -> $new_value
      * @return Collection
      */
     function mapValues($transform) {}
@@ -466,7 +466,7 @@ class Collection implements ArrayAccess, Countable
      * the values obtained by applying the transform function to each entry in this collection.
      *
      * @param Collection $destination
-     * @param callable $transform ($value, $key, $index) -> $new_value
+     * @param callable $transform ($value, $key) -> $new_value
      * @return Collection
      */
     function mapValuesTo($destination, $transform) {}
@@ -482,7 +482,7 @@ class Collection implements ArrayAccess, Countable
      * Returns the first element yielding the largest value of the given function or null if
      * there are no elements.
      *
-     * @param callable $selector ($value, $key, $index) -> $new_value
+     * @param callable $selector ($value, $key) -> $new_value
      * @return mixed
      */
     function maxBy($selector) {}
@@ -507,7 +507,7 @@ class Collection implements ArrayAccess, Countable
      * Returns the first element yielding the smallest value of the given function or null if
      * there are no elements.
      *
-     * @param callable $selector ($value, $key, $index) -> $new_value
+     * @param callable $selector ($value, $key) -> $new_value
      * @return mixed
      */
     function minBy($selector) {}
@@ -576,7 +576,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns true if no elements match the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return bool
      */
     function none($predicate) {}
@@ -604,7 +604,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Performs the given action on each element and returns the collection itself afterwards.
      *
-     * @param callable $action ($value, $key, $index) -> void
+     * @param callable $action ($value, $key) -> void
      * @return Collection
      */
     function onEach($action) {}
@@ -621,7 +621,7 @@ class Collection implements ArrayAccess, Countable
      * elements for which predicate yielded true, while second collection contains elements for
      * which predicate yielded false.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return Pair
      */
     function partition($predicate) {}
@@ -697,7 +697,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Removes all elements from this collection that match the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return bool
      */
     function removeAll($predicate) {}
@@ -705,7 +705,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Retains only elements of this collection that match the given predicate.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return bool
      */
     function retainAll($predicate) {}
@@ -735,7 +735,7 @@ class Collection implements ArrayAccess, Countable
      * Returns the single element matching the given predicate, or null if there is no or more than
      * one matching element.
      *
-     * @param callable $predicate ($value, $key, $index) -> bool
+     * @param callable $predicate ($value, $key) -> bool
      * @return mixed
      */
     function single($predicate) {}
@@ -766,7 +766,7 @@ class Collection implements ArrayAccess, Countable
      * Sorts elements in the collection in-place according to natural sort order of the value returned
      * by specified selector function.
      *
-     * @param callable $selector ($value, $key, $index) -> $new_value
+     * @param callable $selector ($value, $key) -> $new_value
      * @return void
      */
     function sortBy($selector) {}
@@ -775,7 +775,7 @@ class Collection implements ArrayAccess, Countable
      * Sorts elements in the collection in-place descending according to natural sort order of the
      * value returned by specified selector function.
      *
-     * @param callable $selector ($value, $key, $index) -> $new_value
+     * @param callable $selector ($value, $key) -> $new_value
      * @return void
      */
     function sortByDescending($selector) {}
@@ -806,7 +806,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a collection of all elements sorted according to natural sort order of the
      * value returned by specified selector function.
      *
-     * @param callable $selector ($value, $key, $index) -> $new_value
+     * @param callable $selector ($value, $key) -> $new_value
      * @return Collection
      */
     function sortedBy($selector) {}
@@ -815,7 +815,7 @@ class Collection implements ArrayAccess, Countable
      * Returns a collection of all elements sorted descending according to natural sort order
      * of the value returned by specified selector function.
      *
-     * @param callable $selector ($value, $key, $index) -> $new_value
+     * @param callable $selector ($value, $key) -> $new_value
      * @return Collection
      */
     function sortedByDescending($selector) {}
@@ -823,7 +823,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns a collection of all elements sorted descending according to their natural sort order.
      *
-     * @param callable $selector ($value, $key, $index) -> $new_value
+     * @param callable $selector ($value, $key) -> $new_value
      * @return Collection
      */
     function sortedDescending($selector) {}
@@ -855,7 +855,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns a collection containing last elements satisfying the given predicate.
      *
-     * @param $predicate ($value, $key, $index) -> bool
+     * @param $predicate ($value, $key) -> bool
      * @return Collection
      */
     function takeLastWhile($predicate) {}
@@ -863,7 +863,7 @@ class Collection implements ArrayAccess, Countable
     /**
      * Returns a collection containing first elements satisfying the given predicate.
      *
-     * @param $predicate ($value, $key, $index) -> bool
+     * @param $predicate ($value, $key) -> bool
      * @return Collection
      */
     function takeWhile($predicate) {}
diff --git a/tests/001-pair.phpt b/tests/001-pair.phpt
new file mode 100644
index 0000000..1a49e61
--- /dev/null
+++ b/tests/001-pair.phpt
@@ -0,0 +1,9 @@
+--TEST--
+Test Pair.
+--FILE--
+<?php
+$pair = new Pair('foo', 'bar');
+if ($pair->first != 'foo' || $pair->second != 'bar')
+    echo 'Test for Pair failed.', PHP_EOL;
+?>
+--EXPECT--
diff --git a/tests/001-init.phpt b/tests/002-init.phpt
similarity index 53%
rename from tests/001-init.phpt
rename to tests/002-init.phpt
index f70f543..10060d4 100644
--- a/tests/001-init.phpt
+++ b/tests/002-init.phpt
@@ -4,8 +4,9 @@ Test Collection::init().
 <?php
 $array = ['a' => 'b'];
 $collection = Collection::init($array);
-$collection2 = Collection::init($collection);
-if ($array != $collection2->toArray())
+$collection1 = Collection::init($collection);
+$collection2 = Collection::init();
+if ($array != $collection1->toArray() || $collection2->toArray() != [])
     echo 'Collection::init() failed.', PHP_EOL;
 ?>
 --EXPECT--
diff --git a/tests/002-add-all.phpt b/tests/003-add-all.phpt
similarity index 100%
rename from tests/002-add-all.phpt
rename to tests/003-add-all.phpt
diff --git a/tests/003-all.phpt b/tests/004-all-any.phpt
similarity index 51%
rename from tests/003-all.phpt
rename to tests/004-all-any.phpt
index dd6d827..f2dd6a0 100644
--- a/tests/003-all.phpt
+++ b/tests/004-all-any.phpt
@@ -10,10 +10,16 @@ $collection = Collection::init([
 $result = $collection->all(function ($value) {
     return $value < 100;
 });
-$result2 = $collection->all(function ($value, $key) {
+$result1 = $collection->all(function ($value, $key) {
     return strlen($key) < 4;
 });
-if ($result || !$result2)
+$result2 = $collection->any(function ($value) {
+    return $value % 3 == 0;
+});
+$result3 = $collection->any(function ($value, $key) {
+    return strpos($key, 'g') !== false;
+});
+if ($result || !$result1 || !$result2 || $result3)
     echo 'Collection::all() failed.', PHP_EOL;
 ?>
 --EXPECT--