code: def is_primitive(self):
          
          if is_py2:
              return isinstance(
                  self.val, 
                  (
                      types.NoneType,
                      types.BooleanType,
                      types.IntType,
                      types.LongType,
                      types.FloatType
                  )
              )
  
          else:
              return isinstance(
                  self.val,
                  (
                      type(None),
                      bool,
                      int,
                      float
                  )
              )
docs: is the value a built-in type?