Automattic / jetpack

		$builder->setNamespace( __NAMESPACE__ )

			->setName( $function_name )

			->setFunction(

				function() use ( &$args ) {

					$current_args = func_get_args();

					foreach ( $args as $arg ) {

						if ( array_slice( $arg, 0, -1 ) === $current_args ) {

							return array_pop( $arg );

						}

					}

				}

			);

		$mock = $builder->build();

		$builder->setNamespace( __NAMESPACE__ )

			->setName( 'apply_filters' )

			->setFunction(

				function() {

					$current_args = func_get_args();

					foreach ( $this->mocked_filters as $filter ) {

						if ( array_slice( $filter, 0, -1 ) === $current_args ) {

							return array_pop( $filter );

						}

					}

				}

			);

		$this->apply_filters_mock = $builder->build();

		$this->apply_filters_mock->enable();