Removes a given role from this backend.
If the given role is not contained by this backed, this method should not do anything and return null
to denote this.
@param roleName the name of the role to remove, cannot be
null
.
@return the removed role, if it was successfully removed from this backend, or
null
if the role was not contained by this backend or could not be removed.
@throws IllegalArgumentException in case the given argument was
null
;
@throws Exception in case of problems removing the requested role.