def METHOD_NAME(self):
    fake_entity_mapping = {}
    for entity in self.all_tails:
        head = entity.split('_')[0]
        valid_tails = [head + '_' + r for r in self.all_relations]
        clean_subset = [c_t for c_t in valid_tails if c_t != entity]
        fake_entity_mapping[entity] = clean_subset
    return fake_entity_mapping