Where traits may be useful

example.php

<?php

interface InputStream
{
    public function close();
    public function read($numberOfBytes);
    public function skip($numberOfBytes);
}

interface MarkableStream
{
    public function mark();
    public function reset();
}

interface OutputStream
{
    public function close();
    public function write($bytes);
}

trait Closeable
{
    public function close()
    {
        fclose($this->fileDescriptor);
    }
}

trait Markable
{
    // implement mark and reset behavior
}

class FileInputStream implements InputStream, MarkableStream
{
    use Closeable;
    use Markable;
    
    //Implement here FileInputStream behavior
}

class FileOutputStream implements OutputStream
{
    use Closeable;
    
    //Implement here FileInputStream behavior
}