code: def has_metaclass(parent):
      
      for node in parent.children:
          if node.type == syms.suite:
              return has_metaclass(node)
          elif node.type == syms.simple_stmt and node.children:
              expr_node = node.children[0]
              if expr_node.type == syms.expr_stmt and expr_node.children:
                  left_side = expr_node.children[0]
                  if isinstance(left_side, Leaf) and \
                          left_side.value == '__metaclass__':
                      return True
      return False
docs: we have to check the cls_node without changing it.
          There are two possiblities:
            1)  clsdef => suite => simple_stmt => expr_stmt => Leaf('__meta')
            2)  clsdef => simple_stmt => expr_stmt => Leaf('__meta')