Adds a special file that might have a different actual path than
           its address.

        Parameters
        ----------
        mask : string
            The URL that must be matched to perform this request.

        path : string
            The actual file path.

        from_quick_server : bool
            If set the file path is relative to *this* script otherwise it is
            relative to the process.

        ctype : string
            Optional content type.

def add_special_file(self, mask, path, from_quick_server, ctype=None):
        """Adds a special file that might have a different actual path than
           its address.

        Parameters
        ----------
        mask : string
            The URL that must be matched to perform this request.

        path : string
            The actual file path.

        from_quick_server : bool
            If set the file path is relative to *this* script otherwise it is
            relative to the process.

        ctype : string
            Optional content type.
        """
        full_path = path if not from_quick_server else os.path.join(
            os.path.dirname(__file__), path)

        def read_file(_req, _args):
            with open(full_path, 'rb') as f_out:
                return Response(f_out.read(), ctype=ctype)

        self.add_text_get_mask(mask, read_file)
        self.set_file_argc(mask, 0)