<?php

class DummyWrapper
{
    public $context;
    
    public static function register(): void
    {
        \stream_wrapper_register('dummy', self::class);
    }
    
    public function stream_open(string $path, string $mode, int $options, ?string &$opened_path): bool
    {
        $options = \stream_context_get_options($this->context);
        var_dump($options['dummy']['foo']);
        
        return true;
    }
    
    public function stream_stat()
    {
    }
    
    public function stream_read()
    {
    }
    
    public function stream_eof()
    {
    }
}

DummyWrapper::register();
\file_get_contents('dummy://foo', false, \stream_context_create(['dummy' => ['foo' => 'bar']]));
\file_get_contents('php://filter/resource=dummy://foo', false, \stream_context_create(['dummy' => ['foo' => 'bar']]));