code: def visit_Call(self, node):
          
          for alias in self.aliases[node.func]:
              if alias is MODULES['__builtin__']['getattr']:
                  attr_name = node.args[-1].s
                  attribute = attributes[attr_name][-1]
                  self.add(node, attribute.return_range(None))
              elif isinstance(alias, Intrinsic):
                  alias_range = alias.return_range(
                      [self.visit(n) for n in node.args])
                  self.add(node, alias_range)
              else:
                  return self.generic_visit(node)
          return self.result[node]
docs: Function calls are not handled for now.
  
          >>> import gast as ast
          >>> from pythran import passmanager, backend
          >>> node = ast.parse('''
          ... def foo():
          ...     a = __builtin__.range(10)''')
          >>> pm = passmanager.PassManager("test")
          >>> res = pm.gather(RangeValues, node)
          >>> res['a']
          Interval(low=-inf, high=inf)