Clear the dict

def clear(self):
        '''
        Clear the dict
        '''
        with self._lock:
            super(LazyLoader, self).clear()  # clear the lazy loader
            self.loaded_files = set()
            self.missing_modules = {}
            self.loaded_modules = {}
            # if we have been loaded before, lets clear the file mapping since
            # we obviously want a re-do
            if hasattr(self, 'opts'):
                self._refresh_file_mapping()
            self.initial_load = False