def validate_non_negative_integer_or_none(option, value):
 if (value is None):
  return value
 return validate_non_negative_integer(option, value)

def validate_non_negative_integer_or_none ( option , value ) : if ( value is None ) : return value return validate_non_negative_integer ( option , value )
validate that value is a positive integer or 0 or none .