code: def p_const_map(self, p):
          '''const_map : '{' const_map_seq '}' '''
          p[0] = ast.ConstMap(dict(p[2]), p.lineno(1)f p_const_map(self, p):
          '''const_map : '{' const_map_seq '}' '''
          p[0] = ast.ConstMap(dict(p[2]), p.lineno(1))
docs: const_map : '{' const_map_seq '}'