How to fail the test case - Cucumber with Groovy

Hi,
I am new to Cucumber + Groovy and developing the script. When I check the particular cucumber step in the step definition file, if the condition is false, I wanted to make that particular test case should be sopped and fail and continue with the next test case.

Please refer the below code and suggest to fail the test case !! If I have to use the FailureHandling.STOP_ON_FAILURE, how to code the line ??

@When(“User enters the (.*) in the Login”)
def user_enter_userid_in_the_Login(String uid) {
if (uid==‘’)
** /** FAIL the TEST CASE /
else
WebUI.setText(findTestObject(‘Object Repository/ORTC01/Page_/input_userid’), uid,
FailureHandling.STOP_ON_FAILURE)
WebUI.delay(5)
}