code: def call(self, x):
      return x + self.a1 + self.b1
  
file_path: nni/test/ut/nas/space/test_executable_space.py
imports: import sys
  import pytest
  import nni
  from nni.mutable import *
  from nni.mutable.mutable import _mutable_equal
  from nni.nas.evaluator import FunctionalEvaluator, FrozenEvaluator
  from nni.nas.space import *
label_desc: Use image node_id 2 for calling the MyModelSpace obj's underlying member method code with example usage: obj.call(x) and returns: unknown