Update invoke_first & invoke_last documentation. (#207)

* Update `invoke_first` & `invoke_last` documentation.

Closes #156.

* Fix coding style errors so build succeeds.

docs/functional-php.md

@@ -570,10 +570,10 @@ $userId = invoke_if($user, 'getId', [], 0);
 Invokes method `$methodName` on each object in the `$collection` and returns the results of the call
 
 ``mixed Functional\invoke_first(array|Traversable $collection, string $methodName[, array $methodArguments])``
-Invokes method `$methodName` on the first object in the `$collection` and returns the results of the call
+Invokes method `$methodName` on the first object in the `$collection` containing a callable method named `$methodName` and returns the results of the call
 
 ``mixed Functional\invoke_last(array|Traversable $collection, string $methodName[, array $methodArguments])``
-Invokes method `$methodName` on the last object in the `$collection` and returns the results of the call
+Invokes method `$methodName` on the last object in the `$collection` containing a callable method named `$methodName` and returns the results of the call
 
 
 ## invoker()

src/Functional/InvokeFirst.php

@@ -14,12 +14,13 @@
 use Traversable;
 
 /**
- * Calls the method named by $methodName on first value in the collection. Any extra arguments passed to invoke will be
- * forwarded on to the method invocation.
+ * Calls the method named by $methodName on first object in the collection containing a callable method named
+ * $methodName. Any extra arguments passed to invoke will be forwarded on to the method invocation.
  *
  * @param Traversable|array $collection
  * @param string $methodName
  * @param array $arguments
+ *
  * @return mixed
  */
 function invoke_first($collection, $methodName, array $arguments = [])

src/Functional/InvokeLast.php

@@ -14,8 +14,8 @@
 use Functional\Exceptions\InvalidArgumentException;
 
 /**
- * Calls the method named by $methodName on last value in the collection. Any extra arguments passed to invoke will be
- * forwarded on to the method invocation.
+ * Calls the method named by $methodName on last object in the collection containing a callable method named
+ * $methodName. Any extra arguments passed to invoke will be forwarded on to the method invocation.
  *
  * @param Traversable|array $collection
  * @param string $methodName

src/Functional/Noop.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Copyright (C) 2011-2017 by Lars Strojny <[email protected]>
  *
@@ -20,6 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 namespace Functional;
 
 /**