presto-spi/src/main/java/io/prestosql/spi/procedure/Procedure.java/Procedure/checkNotNullOrEmpty
class Procedure:    private static String checkNotNullOrEmpty(String value, String name)
    {
        requireNonNull(value, name + " is null");
        checkArgument(!value.isEmpty(), name + " is empty");
        return value;
    }