code: def test_filesize(self):
      filename = os.path.join(self.get_temp_dir(), "test.txt")
      with open(filename, "w") as file:
          file.write("Hello! \n")
      self.assertEqual(metrics.CalculateFileSize(filename), 0)
  
imports: import os
  from tensorflow.core.framework import summary_pb2
  from tensorflow.core.framework import versions_pb2
  from tensorflow.core.protobuf import fingerprint_pb2
  from tensorflow.python.eager import test
  from tensorflow.python.saved_model.pywrap_saved_model import metrics
label_desc: Use image node_id 10 for calling the MetricsTest obj's underlying member method code with example usage: obj.test_filesize() without return types