code: def _set_description(self, schema):
          
          if schema is None:
              self.description = None
              return
  
          self.description = tuple(
              [
                  Column(
                      name=field.name,
                      type_code=field.field_type,
                      display_size=None,
                      internal_size=None,
                      precision=None,
                      scale=None,
                      null_ok=field.is_nullable,
                  )
                  for field in schema
              ]
          )
docs: Set description from schema.
  
          :type schema: Sequence[google.cloud.bigquery.schema.SchemaField]
          :param schema: A description of fields in the schema.