static Object ensureNotNull(Location location,Object value){
  if (value == null) {
    throw new EvalException(location,"Snippet runtime does not support null values.");
  }
  return value;
}

static Object ensureNotNull ( Location location , Object value ) { if ( value == null ) { throw new EvalException ( location , "Snippet runtime does not support null values." ) ; } return value ; }
ensure the given value is not null and return it .
