code: def test_request_after_compute_raise_exception(self):
      budget_accountant = PLDBudgetAccountant(
          total_epsilon=1, total_delta=1e-6
      )
      budget_accountant.request_budget(
          mechanism_type=MechanismType.LAPLACE
      )
      budget_accountant.compute_budgets()
      with self.assertRaises(Exception):
          # Budget can not be requested after it has been already computed.
          budget_accountant.request_budget(
              mechanism_type=MechanismType.LAPLACE
          )
  
imports: import sys
  import unittest
  from dataclasses import dataclass
  from pipeline_dp.budget_accounting import MechanismSpec
  from pipeline_dp.aggregate_params import MechanismType
  from pipeline_dp.budget_accounting import NaiveBudgetAccountant
  from pipeline_dp.budget_accounting import PLDBudgetAccountant
  from absl.testing import parameterized
label_desc: Use image node_id 7 for calling the PLDBudgetAccountantTest obj's underlying member method code with example usage: obj.test_request_after_compute_raise_exception() without return types