class_docstr: Test InMemoryDocumentStore's specific features
class_docstr_tok: ["Test","InMemoryDocumentStore","'s","specific","features"]
code: def test_embedding_retrieval_no_embeddings(self, caplog):
      caplog.set_level(logging.WARNING)
      docstore = InMemoryDocumentStore()
      docs = [
          Document(content="Hello world"),
          Document(content="Haystack supports multiple languages"),
      ]
      docstore.write_documents(docs)
      results = docstore.embedding_retrieval(
          query_embedding=[0.1, 0.1, 0.1, 0.1]
      )
      assert len(results) == 0
      assert (
          "No Documents found with embeddings. Returning empty list."
          in caplog.text
      )
  
imports: import logging
  from unittest.mock import patch
  import pandas
  import pytest
  from haystack import Document
  from haystack.document_stores.errors import DocumentStoreError, DuplicateDocumentError
  from haystack.document_stores.in_memory import InMemoryDocumentStore
  from haystack.testing.document_store import DocumentStoreBaseTests
label_desc: Use image node_id 22 for calling the TestMemoryDocumentStore obj's underlying member method code with example usage: obj.test_embedding_retrieval_no_embeddings(caplog) without return types