presto-parser/src/main/java/io/prestosql/sql/parser/AstBuilder.java/AstBuilder/visitSetRole
class AstBuilder:    @Override
    public Node visitSetRole(SqlBaseParser.SetRoleContext context)
    {
        SetRole.Type type = SetRole.Type.ROLE;
        if (context.ALL() != null) {
            type = SetRole.Type.ALL;
        }
        else if (context.NONE() != null) {
            type = SetRole.Type.NONE;
        }
        return new SetRole(getLocation(context), type, getIdentifierIfPresent(context.role));
    }