code: def _transform_item(self, content_metadata_item):
          
          content_metadata_type = content_metadata_item['content_type']
          transformed_item = {}
          for integrated_channel_schema_key, edx_data_schema_key in self.DATA_TRANSFORM_MAPPING.items():
              # Look for transformer functions defined on subclasses.
              # Favor content type-specific functions.
              transformer = (
                  getattr(
                      self,
                      'transform_{content_type}_{edx_data_schema_key}'.format(
                          content_type=content_metadata_type,
                          edx_data_schema_key=edx_data_schema_key
                      ),
                      None
                  )
                  or
                  getattr(
                      self,
                      'transform_{edx_data_schema_key}'.format(
                          edx_data_schema_key=edx_data_schema_key
                      ),
                      None
                  )
              )
              if transformer:
                  transformed_item[integrated_channel_schema_key] = transformer(content_metadata_item)
              else:
                  # The concrete subclass does not define an override for the given field,
                  # so just use the data key to index the content metadata item dictionary.
                  try:
                      transformed_item[integrated_channel_schema_key] = content_metadata_item[edx_data_schema_key]
                  except KeyError:
                      # There may be a problem with the DATA_TRANSFORM_MAPPING on
                      # the concrete subclass or the concrete subclass does not implement
                      # the appropriate field tranformer function.
                      LOGGER.exception(
                          'Failed to transform content metadata item field [%s] for [%s]: [%s]',
                          edx_data_schema_key,
                          self.enterprise_customer.name,
                          content_metadata_item,
                      )
  
          return transformed_item
docs: Transform the provided content metadata item to the schema expected by the integrated channel.