code: def merge(self, docs, **kwargs):
      return docs
  
file_path: jina/tests/unit/orchestrate/flow/flow-orchestrate/test_flow_merge.py
imports: import random
  import pytest
  from jina import Flow, Executor, requests, Document
  from tests import random_docs, validate_callback
label_desc: Use image node_id 1 for calling the Merger obj's underlying member method code with example usage: obj.merge(docs) and returns: docs