class_docstr: Test the dunder methods.
docstr: Check that a transform program is falsy if empty and truthy if not.
docstr_tok: ["Check","that","a","transform","program","is","falsy","if","empty","and","truthy","if","not","."]
code: def test_bool(self):
      """Check that a transform program is falsy if empty and truthy if not."""
      empty_prog = TransformProgram()
      assert not empty_prog
  
      transform1 = TransformContainer(transform=first_valid_transform)
      populated_prog = TransformContainer((transform1,))
      assert populated_prog
  
imports: from typing import Sequence, Callable
  import pytest
  import pennylane
  from pennylane.tape import QuantumScript
  from pennylane.transforms.core import transform, TransformProgram, TransformError, TransformContainer
  from pennylane.transforms.core.transform_program import _batch_postprocessing, _apply_postprocessing_stack, null_postprocessing
  from pennylane.typing import ResultBatch, Result
label_desc: Use image node_id 1 for calling the TestTransformProgramDunders obj's underlying member method code with example usage: obj.test_bool() without return types