code: def test_single_output(self):
      def f(n):
          if n > 0:
              n = -n
          return n
  
      self.assertTransformedResult(f, custom_constant(1), -1)
  
imports: import collections
  from nvidia.dali._autograph.converters import break_statements
  from nvidia.dali._autograph.converters import continue_statements
  from nvidia.dali._autograph.converters import control_flow
  from nvidia.dali._autograph.core import converter_testing
  from nvidia.dali._autograph.utils.all_utils import custom_constant
label_desc: Use image node_id 3 for calling the IfStatementTest obj's underlying member method code with example usage: obj.test_single_output() and returns: n