docstr: Test simple TF feature calculation.
docstr_tok: ["Test","simple","TF","feature","calculation","."]
code: def testPlainTfFeatureCalculation(self):
      """Test simple TF feature calculation."""
      feature_output = self.BuildAndRunTfGraph(tflite_compatible=False)
      # Only one patch returned.
      self.assertEqual(1, feature_output.shape[0])
      self.VerifyMelSpectrumPatch(feature_output[0])
  
imports: import tempfile
  from magenta.models.onsets_frames_transcription import melspec_input
  import numpy
  import tensorflow.compat.v1
label_desc: Use image node_id 7 for calling the MelspecInputTest obj's underlying member method code with example usage: obj.testPlainTfFeatureCalculation() without return types