code: def test_config(self):
      self.run_class_serialization_test(
          metrics.BinaryCrossentropy(
              name="bce", dtype="int32", label_smoothing=0.2
          )
      )
  
imports: import numpy
  from keras import metrics
  from keras import testing
label_desc: Use image node_id 1 for calling the BinaryCrossentropyTest obj's underlying member method code with example usage: obj.test_config() without return types