code: def _slice(self, slicer):
          
          if isinstance(slicer, tuple):
              col, loc = slicer
              if not com.is_null_slice(col) and col != 0:
                  raise IndexError("{0} only contains one item".format(self))
              return self.values[loc]
          return self.values[slicer]
docs: return a slice of my values