code: def mutate(self, node, index):
          
  
          assert index < len(OFFSETS), 'received count with no associated offset'
          assert isinstance(node, parso.python.tree.Number)
  
          val = eval(node.value) + OFFSETS[index]  # pylint: disable=W0123
          return parso.python.tree.Number(' ' + str(val), node.start_pos)
docs: Modify the numeric value on `node`.