presto-parser/src/main/java/io/prestosql/sql/tree/FrameBound.java/FrameBound/FrameBound
class FrameBound:    private FrameBound(Optional<NodeLocation> location, Type type, Expression value)
    {
        super(location);
        this.type = requireNonNull(type, "type is null");
        this.value = Optional.ofNullable(value);
    }