[keycloak-user] updateCredential-method: relevance of output true or false

Hello Could you please explain the meaning of the boolean result of boolean updateCredential(RealmModel realm, UserModel user, CredentialInput input); in package org.keycloak.credential.CredentialInputUpdater (Keycloak 2.4.0 Final)? It's not obvious to me, if there are any differences in Keycloak's behaviour between returning true or false when overriding the method in a customized federation provider, whereas I realized that errorhandling can be triggered by throwing an exception. Thanks in advance, Eduard Matuszak