code: def set_cell(self, index, value):
          
          if self._sort:
              exists, i = sorted_exists(self._index, index)
              if not exists:
                  self._insert_row(i, index)
          else:
              try:
                  i = self._index.index(index)
              except ValueError:
                  i = len(self._index)
                  self._add_row(index)
          self._data[i] = value
docs: Sets the value of a single cell. If the index is not in the current index then a new index will be created.
  
          :param index: index value
          :param value: value to set
          :return: nothing