@param string|HandlerInterface $name

@return HandlerInterface|null
160354
public function find( $name ) {

		if ( ! is_array( $this->initialized ) ) {
			$this->initialized = [];

			/**
			 * Fires right before the first handler is to be registered.
			 *
			 * @param HandlersRegistry $handlers_registry
			 */
			do_action( self::ACTION_REGISTER, $this );
		}

		$name = $name instanceof HandlerInterface ? spl_object_hash( $name ) : (string) $name;

		if ( ! $this->has_handler( $name ) ) {
			return NULL;
		}

		$handler = $this->handlers[ $name ];

		if ( ! in_array( $name, $this->initialized, TRUE ) ) {
			$this->initialized[] = $name;

			/**
			 * Fires right after a handler has been registered.
			 *
			 * @param HandlerInterface   $handler
			 * @param string             $name
			 * @param ProcessorsRegistry $processors_registry
			 */
			do_action( self::ACTION_SETUP, $handler, $name, $this->processors_registry );
		}

		return $handler;
	}
684977
public function parameter(string $name): ?string
    {
        if (isset($this->parameters[$name])) {
            return $this->parameters[$name];
        }

        return null;
    }
76062
public function getFunction($name)
    {
        if (!$this->initialized) {
            $this->initialize();
        }

        return isset($this->functions[$name]) ? $this->functions[$name] : null;
    }
447799
public function getHandlers($name = null)
    {
        $result = is_null($name) ? $this->handlers : $this->handlers[$name];

        return $result;
    }
986341
public function has_handler( $name ) {

		$name instanceof HandlerInterface and $name = spl_object_hash( $name );

		return is_string( $name ) && array_key_exists( $name, $this->handlers );
	}
446103
public function getServer(string $name)
    {
        $name = strtoupper($name);
        foreach ($this->server as $current => $value) {
            if ($current == $name) {
                return $value;
            }
        }

        return null;
    }
285397
public function get(string $name): ?UploadedFileInterface
    {
        if (!isset($this->uploadedFiles[$name])) {
            return null;
        }

        return $this->uploadedFiles[$name];
    }
85658
public static function create($name)
    {
        $class = App::className($name, 'Middleware/UnauthorizedHandler', 'Handler');
        if (!$class) {
            $message = sprintf('Handler `%s` does not exist.', $name);
            throw new RuntimeException($message);
        }

        $instance = new $class();
        if (!$instance instanceof HandlerInterface) {
            $message = sprintf('Handler should implement `%s`, got `%s`.', HandlerInterface::class, get_class($instance));
            throw new RuntimeException($message);
        }

        return $instance;
    }
1216834
public function get($name)
    {
        if ($this->argument->defined($name)) {
            return $this->argument->get($name);
        }
        return null;
    }
383725
public function get(string $name)
    {
        if (!array_key_exists($name, $this->headers)) {
            return null;
        }

        return $this->headers[$name];
    }
1083423
protected function resolveUnknown(/*# string */ $name)
    {
        // warn if reference unknown
        $this->throwError(
            Message::get(Message::CONFIG_REFERENCE_UNKNOWN, $name),
            Message::CONFIG_REFERENCE_UNKNOWN
        );

        return null;
    }
821688
public function findRequest(string $name)
    {
        foreach ($this->actions as $action) {
            if ($action->getRequest()->getName() === $name) {
                return $action->getRequest();
            }
        }

        return null;
    }
1037556
public function getHeader($name)
    {
        $headers = $this->message->getHeaders();
        return isset($headers[$name]) ? $headers[$name] : null;
    }
884228
public function get_param($name) {
        if (array_key_exists($name, $this->params)) {
            return $this->params[$name];
        } else {
            return null;
        }
    }
557573
public function get($name) {
        return isset($this->metadata[$name]) ? $this->metadata[$name] : null;
    }
1153071
public function get($name)
    {
        $name = strtoupper($name);
        if (isset($_SERVER[$name])) {
            return $_SERVER[$name];
        }
        return null;
    }
279109
public function getParameter($name)
    {
        if (isset($this->_parameters[$name])) {
            return $this->_parameters[$name];
        }
        return null;
    }