def check_duplicates():
 s3.prep = (lambda r: (r.method == 'check_duplicates'))
 return s3_rest_controller(module, 'person')

def check_duplicates ( ) : s3 . prep = ( lambda r : ( r . method == 'check_duplicates' ) ) return s3_rest_controller ( module , 'person' )
person rest controller - limited to just check_duplicates for use in s3addpersonwidget2 - allows differential access permissions .