text: import numpy as np
  import pytest
  
  from infiniteremixer.remix.featureretriever import FeatureRetriever
  
  
  @pytest.fixture
  def feature_retriever():
      feature_retriever = FeatureRetriever()
      feature_retriever.mapping = ["beat1", "beat2", "beat3"]
      feature_retriever.features = np.array([[1, 2], [2, 3], [3, 4]])
      return feature_retriever
  
  
  def test_feature_retriever_is_instantiated(feature_retriever):
      assert isinstance(feature_retriever, FeatureRetriever)
  
  
  def test_feature_vector_is_returned(feature_retriever):
      feature_vector = feature_retriever.get_feature_vector("beat1")
      expected_feature_vector = np.array([1, 2])
      assert np.array_equal(feature_vector, expected_feature_vector)
  