code: def add(self, val):
          
          if not isinstance(val, six.integer_types):
              raise ValueError("CumulativePointLong only supports integer types")
          if val > 0:
              super(CumulativePointLong, self).add(val)
docs: Add `val` to the current value if it's positive.
  
          Return without adding if `val` is not positive.
  
          :type val: int
          :param val: Value to add.