Mark all classes as final

src/CompositeStream.php

@@ -4,7 +4,7 @@
 
 use Evenement\EventEmitter;
 
-class CompositeStream extends EventEmitter implements DuplexStreamInterface
+final class CompositeStream extends EventEmitter implements DuplexStreamInterface
 {
     protected $readable;
     protected $writable;

src/DuplexResourceStream.php

@@ -6,7 +6,7 @@
 use React\EventLoop\LoopInterface;
 use InvalidArgumentException;
 
-class DuplexResourceStream extends EventEmitter implements DuplexStreamInterface
+final class DuplexResourceStream extends EventEmitter implements DuplexStreamInterface
 {
     private $stream;
     private $loop;

src/ReadableResourceStream.php

@@ -6,7 +6,7 @@
 use React\EventLoop\LoopInterface;
 use InvalidArgumentException;
 
-class ReadableResourceStream extends EventEmitter implements ReadableStreamInterface
+final class ReadableResourceStream extends EventEmitter implements ReadableStreamInterface
 {
     /**
      * @var resource

src/ThroughStream.php

@@ -73,7 +73,7 @@
  * @see DuplexStreamInterface::close()
  * @see WritableStreamInterface::pipe()
  */
-class ThroughStream extends EventEmitter implements DuplexStreamInterface
+final class ThroughStream extends EventEmitter implements DuplexStreamInterface
 {
     private $readable = true;
     private $writable = true;

src/Util.php

@@ -2,7 +2,7 @@
 
 namespace React\Stream;
 
-class Util
+final class Util
 {
     /**
      * Pipes all the data from the given $source into the $dest

src/WritableResourceStream.php

@@ -5,7 +5,7 @@
 use Evenement\EventEmitter;
 use React\EventLoop\LoopInterface;
 
-class WritableResourceStream extends EventEmitter implements WritableStreamInterface
+final class WritableResourceStream extends EventEmitter implements WritableStreamInterface
 {
     private $stream;
     private $loop;