code: def unselectRow(self, row):
          'Unselect given row, return True if selected; else return False. O(log n)'
          if id(row) in self._selectedRows:
              del self._selectedRows[id(row)]
              return True
          else:
              return Falsf unselectRow(self, row):
          'Unselect given row, return True if selected; else return False. O(log n)'
          if id(row) in self._selectedRows:
              del self._selectedRows[id(row)]
              return True
          else:
              return False
docs: Unselect given row, return True if selected; else return False. O(log n)