Register the given dependent as depending on the "resource"
        named by resource_name.

def register(self, resource_name, dependent=None):
        '''
        Register the given dependent as depending on the "resource"
        named by resource_name.
        '''
        if dependent is None:
            # Give a partial usable as a decorator
            return partial(self.register, resource_name)

        dependent = self._unwrap_dependent(dependent)
        self._register_dependent(dependent, resource_name)
        self._register_resource_dependency(resource_name, dependent)

        # Return dependent to ease use as decorator
        return dependent