code: def testMergeDetails(self):
      a = text_format.Parse(
          """
          validation_details {
            slicing_details {
              slicing_spec {}
              num_matching_slices: 1
            }
            slicing_details {
              slicing_spec {
                feature_keys: ["x", "y"]
              }
              num_matching_slices: 1
            }
          }""",
          validation_result_pb2.ValidationResult(),
      )
  
      b = text_format.Parse(
          """
          validation_details {
            slicing_details {
              slicing_spec {
                feature_keys: ["x"]
              }
              num_matching_slices: 1
            }
            slicing_details {
              slicing_spec {
                feature_keys: ["x", "y"]
              }
              num_matching_slices: 2
            }
          }""",
          validation_result_pb2.ValidationResult(),
      )
  
      expected = text_format.Parse(
          """
          validation_details {
            slicing_details {
              slicing_spec {}
              num_matching_slices: 1
            }
            slicing_details {
              slicing_spec {
                feature_keys: ["x", "y"]
              }
              num_matching_slices: 3
            }
            slicing_details {
              slicing_spec {
                feature_keys: ["x"]
              }
              num_matching_slices: 1
            }
          }""",
          validation_result_pb2.ValidationResult(),
      )
  
      metrics_validator.merge_details(a, b)
      self.assertProtoEquals(expected, a)
  
imports: from absl.testing import parameterized
  import tensorflow
  from tensorflow_model_analysis.api import types
  from tensorflow_model_analysis.eval_saved_model import testutil
  from tensorflow_model_analysis.evaluators import metrics_validator
  from tensorflow_model_analysis.metrics import metric_types
  from tensorflow_model_analysis.proto import config_pb2
  from tensorflow_model_analysis.proto import validation_result_pb2
  from tensorflow_model_analysis.slicer import slicer_lib
  from google.protobuf import text_format
label_desc: Use image node_id 17 for calling the MetricsValidatorTest obj's underlying member method code with example usage: obj.testMergeDetails() without return types