code: def test_straightline(self):
      def f(x):
          return x * x
  
      self.assertTransformedEquivalent(f, 2)
  
imports: from tensorflow.python.autograph.converters import functions
  from tensorflow.python.autograph.converters import return_statements
  from tensorflow.python.autograph.core import converter_testing
  from tensorflow.python.framework import ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the SingleReturnTest obj's underlying member method code with example usage: obj.test_straightline() and returns: unknown