text: from mappings import map_measurement
  
  
  class TestMeasurement():
  
      __nullable_fields = [
          "measurement_datetime", "value_as_number", "provider_id",
          "visit_occurrence_id", "unit_source_value"
      ]
      expected_fields = [
          "measurement_id", "person_id", "measurement_concept_id",
          "measurement_date", "measurement_type_concept_id",
          "measurement_datetime", "value_as_number", "provider_id",
          "visit_occurrence_id", "unit_source_value"
      ]
  
      def test_field_names(self, data_frame):
          actual_fields = map_measurement(data_frame).columns
          # Test whether column names exist in dataframe
          assert(
              set(actual_fields) == set(self.expected_fields)
          ), \
              "Resulting columns did not match the expected columns: %s"\
              % self.expected_fields
  
      # def test_datetime(self, spark_session):
      #     TODO
  
      # def test_blood_pressures(self, spark_session):
      #     TODO
  