code: def test_factory_behavior(mock_sentence_transformer):
      embedding_backend = _SentenceTransformersEmbeddingBackendFactory.get_embedding_backend(
          model="my_model", device="cpu"
      )
      same_embedding_backend = _SentenceTransformersEmbeddingBackendFactory.get_embedding_backend(
          "my_model", "cpu"
      )
      another_embedding_backend = _SentenceTransformersEmbeddingBackendFactory.get_embedding_backend(
          model="another_model", device="cpu"
      )
  
      assert same_embedding_backend is embedding_backend
      assert another_embedding_backend is not embedding_backend
  
imports: from unittest.mock import patch
  import pytest
  from haystack.components.embedders.backends.sentence_transformers_backend import _SentenceTransformersEmbeddingBackendFactory
label_desc: Use image node_id 1 for calling a global function with example usage: test_factory_behavior(mock_sentence_transformer) without return types