code: def to_api_repr(self):
          
  
          source_refs = [
              {
                  "projectId": table.project,
                  "datasetId": table.dataset_id,
                  "tableId": table.table_id,
              }
              for table in self.sources
          ]
  
          configuration = self._configuration.to_api_repr()
          _helpers._set_sub_prop(configuration, ["copy", "sourceTables"], source_refs)
          _helpers._set_sub_prop(
              configuration,
              ["copy", "destinationTable"],
              {
                  "projectId": self.destination.project,
                  "datasetId": self.destination.dataset_id,
                  "tableId": self.destination.table_id,
              },
          )
  
          return {
              "jobReference": self._properties["jobReference"],
              "configuration": configuration,
          }
docs: Generate a resource for :meth:`_begin`.