presto-parser/src/main/java/io/prestosql/sql/parser/AstBuilder.java/AstBuilder/visitShowSession
class AstBuilder:    @Override
    public Node visitShowSession(SqlBaseParser.ShowSessionContext context)
    {
        return new ShowSession(getLocation(context),
                getTextIfPresent(context.pattern)
                        .map(AstBuilder::unquote),
                getTextIfPresent(context.escape)
                        .map(AstBuilder::unquote));
    }