No implicit nullables, code style updates

src/functions.php

@@ -19,7 +19,7 @@
 
 namespace Pipeline;
 
-function map(callable $func = null): Standard
+function map(?callable $func = null): Standard
 {
     $pipeline = new Standard();
 
@@ -30,7 +30,7 @@ function map(callable $func = null): Standard
     return $pipeline->map($func);
 }
 
-function take(iterable $input = null, iterable ...$inputs): Standard
+function take(?iterable $input = null, iterable ...$inputs): Standard
 {
     $pipeline = new Standard($input);
 

tests/EachTest.php

@@ -22,7 +22,6 @@
 use LogicException;
 use PHPUnit\Framework\TestCase;
 use Pipeline\Standard;
-
 use ArrayIterator;
 
 use function Pipeline\map;

tests/StaticAnalysisTest.php

@@ -71,7 +71,7 @@ public function testAllMethodsArePublicOrPrivate(ReflectionMethod $method): void
      */
     public function testInterfaceCompatibilityPHP71(): void
     {
-        $example = new class () extends Standard {
+        $example = new class extends Standard {
             private $input;
 
             public function __construct(iterable $input = null)

tests/TuplesTest.php

@@ -21,7 +21,6 @@
 
 use ArrayIterator;
 use PHPUnit\Framework\TestCase;
-
 use Pipeline\Standard;
 use IteratorIterator;