presto-spi/src/main/java/io/prestosql/spi/expression/FieldDereference.java/FieldDereference/FieldDereference
class FieldDereference:    public FieldDereference(Type type, ConnectorExpression target, int field)
    {
        super(type);
        this.target = requireNonNull(target, "target is null");
        this.field = field;
    }