presto-parser/src/main/java/io/prestosql/sql/tree/ShowRoles.java/ShowRoles/ShowRoles
class ShowRoles:    public ShowRoles(Optional<NodeLocation> location, Optional<Identifier> catalog, boolean current)
    {
        super(location);
        this.catalog = requireNonNull(catalog, "catalog is null");
        this.current = current;
    }