code: def test_warning_if_meta_not_found(self, caplog):
      ranker = MetaFieldRanker(meta_field="rating")
      docs_before = [
          Document(id="1", content="abc", meta={"wrong_field": 1.3})
      ]
      with caplog.at_level(logging.WARNING):
          ranker.run(documents=docs_before)
          assert (
              "The parameter <meta_field> is currently set to 'rating', but none of the provided Documents with IDs 1 have this meta key."
              in caplog.text
          )
  
imports: import pytest
  import logging
  from haystack import Document
  from haystack.components.rankers.meta_field import MetaFieldRanker
label_desc: Use image node_id 8 for calling the TestMetaFieldRanker obj's underlying member method code with example usage: obj.test_warning_if_meta_not_found(caplog) without return types