code: def set_primary_key(self, columns, index_name=False):
          
          self._add_index(
              self._create_index(columns, index_name or "primary", True, True)
          )
  
          for column_name in columns:
              column = self.get_column(column_name)
              column.set_notnull(True)
  
          return self
docs: Set the primary key.
  
          :type columns: list
          :type index_name: str or bool
  
          :rtype: Table