def METHOD_NAME(self, ecr_repo_mock):
    companion_stack_name = "CompanionStackA"
    function_a = "FunctionA"
    repo_logical_id = "RepoLogicalIDA"
    repo_physical_id = "RepoPhysicalIDA"
    repo_output_id = "RepoOutputIDA"
    ecr_repo_instance = ecr_repo_mock.return_value
    ecr_repo_instance.logical_id = repo_logical_id
    ecr_repo_instance.physical_id = repo_physical_id
    ecr_repo_instance.output_logical_id = repo_output_id
    companion_stack = Mock()
    companion_stack.stack_name = companion_stack_name
    builder = CompanionStackBuilder(companion_stack)
    builder.add_function(function_a)
    template = builder.build()
    self.assertIn(f'"{repo_logical_id}":', template)
    self.assertIn(f'"RepositoryName": "{repo_physical_id}"', template)
    self.assertIn(f'"{repo_output_id}":', template)