code: def test_null_return(self):
      def f(n):
          if n > 4:
              return
          return
  
      self.assertTransformedEquivalent(f, 4)
      self.assertTransformedEquivalent(f, 5)
  
imports: from nvidia.dali._autograph.converters import functions
  from nvidia.dali._autograph.converters import return_statements
  from nvidia.dali._autograph.core import converter_testing
label_desc: Use image node_id 18 for calling the SingleReturnTest obj's underlying member method code with example usage: obj.test_null_return() without return types