docs: def flags(self, index):
          """Override Qt method"""
          column = index.column()
  
          if index.isValid():
              if column in [C.COL_START, C.COL_END]:
  #                return Qt.ItemFlags(Qt.ItemIsEnabled | Qt.ItemIsSelectable)
                  return Qt.ItemFlags(Qt.ItemIsEnabled)
              else:
                  return Qt.ItemFlags(Qt.ItemIsEnabled | Qt.ItemIsSelectable)
  #                return Qt.ItemFlags(Qt.ItemIsEnabled)
          else:
              return Qt.ItemFlags(Qt.ItemIsEnabled)