Merge branch 'niden-T13907-collection-psr7' into 4.0.x

* niden-T13907-collection-psr7:
  [#13907] - Changing internal to private to check the Windows build
  [#13907] - Added more tests initializing headers with a collection
  [#13907] - Added the ability to pass a collection object and array
  [#13907] - Added Collection for headers and attributes
  [#13907] - Refactoring response
  [#13907] - Incorporated Collection to the Request
  [4.0.x] - Changed the constructor to use memory instead of temp
  [4.0.x] - Corrected return value for get
  [#13907] - Added the ability to pass a collection object and array
  [#13907] - Added Collection for headers and attributes
  [#13907] - Refactoring response
  [#13907] - Incorporated Collection to the Request
  [4.0.x] - Changed the constructor to use memory instead of temp
  [4.0.x] - Corrected return value for get

CHANGELOG-4.0.md

@@ -23,6 +23,7 @@ The implementation offers PSR-7/PSR-17 compatible components in a different name
     - `Phalcon\Helper\Number`
 [#13889](https://github.com/phalcon/cphalcon/pull/13889)
 - Added `Phalcon\Collection`, an object implementing `ArrayAccess`, `Countable`, `IteratorAggregate`, `JsonSerializable`, `Serializable`, offering an easy way to handle collections of data such as arrays, superglobals etc. [#13886](https://github.com/phalcon/cphalcon/issues/13886)
+- Added `Phalcon\Collection`, in `Phalcon\Http\Message\Request` and `Phalcon\Http\Message\ServerRequest` to handle the headers [#13907](https://github.com/phalcon/cphalcon/issues/13907)
 
 ## Fixed
 - Fixed `Phalcon\Image\Adapter\Imagick::_watermark`, `setImageAlpha()` fills the alpha channel with black before execution (replaced by `evaluateImage()`). Improved imagick compatibility. [#13911](https://github.com/phalcon/cphalcon/pull/13911)

phalcon/collection.zep

@@ -91,12 +91,12 @@ class Collection implements \ArrayAccess, \Countable, \IteratorAggregate, \JsonS
 	/**
 	 * Get the element from the collection
 	 */
-	public function get(string! element, var defaultValue = null, bool insensitive = true) -> var | bool
+	public function get(string! element, var defaultValue = null, bool insensitive = true) -> var
 	{
 		var value;
 
 		if likely insensitive {
-			let element = strtolower(element);
+			let element = element->lower();
 		}
 
 		if likely fetch value, this->lowerKeys[element] {
@@ -120,7 +120,7 @@ class Collection implements \ArrayAccess, \Countable, \IteratorAggregate, \JsonS
 	public function has(string! element, bool insensitive = true) -> bool
 	{
 		if likely insensitive {
-			let element = strtolower(element);
+			let element = element->lower();
 		}
 
 		return isset this->lowerKeys[element];
@@ -209,7 +209,7 @@ class Collection implements \ArrayAccess, \Countable, \IteratorAggregate, \JsonS
 
 		if this->has(element) {
 			if likely insensitive {
-				let element = strtolower(element);
+				let element = element->lower();
 			}
 
 			let value = lowerKeys[element];
@@ -239,7 +239,7 @@ class Collection implements \ArrayAccess, \Countable, \IteratorAggregate, \JsonS
 	{
 		var key;
 
-		let key = strtolower(element);
+		let key = element->lower();
 
 		let this->data[element]  = value,
 			this->lowerKeys[key] = element;