presto-parser/src/main/java/io/prestosql/sql/tree/Explain.java/Explain/Explain
class Explain:    private Explain(Optional<NodeLocation> location, boolean analyze, boolean verbose, Statement statement, List<ExplainOption> options)
    {
        super(location);
        this.statement = requireNonNull(statement, "statement is null");
        this.analyze = analyze;
        this.verbose = verbose;
        if (options == null) {
            this.options = ImmutableList.of();
        }
        else {
            this.options = ImmutableList.copyOf(options);
        }
    }