<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def create_experiment_summary():
 """Returns a summary proto buffer holding this experiment."""


  # Convert TEMPERATURE_LIST to google.protobuf.ListValue
  temperature_list = struct_pb2.ListValue()
  temperature_list.extend(TEMPERATURE_LIST)
  materials = struct_pb2.ListValue()
  materials.extend(HEAT_COEFFICIENTS.keys())
  return summary.experiment_pb(
      hparam_infos=[
          api_pb2.HParamInfo(name='initial_temperature',
                             display_name='Initial temperature',
                             type=api_pb2.DATA_TYPE_FLOAT64,
                             domain_discrete=temperature_list),
          api_pb2.HParamInfo(name='ambient_temperature',
                             display_name='Ambient temperature',
                             type=api_pb2.DATA_TYPE_FLOAT64,
                             domain_discrete=temperature_list),
          api_pb2.HParamInfo(name='material',
                             display_name='Material',
                             type=api_pb2.DATA_TYPE_STRING,
                             domain_discrete=materials)
      ],
      metric_infos=[
          api_pb2.MetricInfo(
              name=api_pb2.MetricName(
                  tag='temperature/current/scalar_summary'),
              display_name='Current Temp.'),
          api_pb2.MetricInfo(
              name=api_pb2.MetricName(
                  tag='temperature/difference_to_ambient/scalar_summary'),
              display_name='Difference To Ambient Temp.'),
          api_pb2.MetricInfo(
              name=api_pb2.MetricName(
                  tag='delta/scalar_summary'),
              display_name='Delta T')
      ]
  )