<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def loads(self, config, content, prefer=None):
 """ An abstract loads method which loads an instance from some content. :param class config: The config class to load into :param str content: The content to load from :param str prefer: The preferred serialization module name :raises ValueError: If load handler does not provided handler method :return: A dictionary converted from the given content :rtype: dict """


        loader = self._prefer_package(prefer)
        loads_hook_name = f"on_{loader}_loads"
        loads_hook = getattr(self, loads_hook_name, None)
        if not callable(loads_hook):
            raise ValueError(
                f"no loads handler for {self.imported!r}, requires method "
                f"{loads_hook_name!r} in {self!r}"
            )
        return loads_hook(self.handler, config, content)