presto-parser/src/main/java/io/prestosql/sql/SqlFormatter.java/Formatter/visitSelect
class Formatter:        @Override
        protected Void visitSelect(Select node, Integer indent)
        {
            append(indent, "SELECT");
            if (node.isDistinct()) {
                builder.append(" DISTINCT");
            }

            if (node.getSelectItems().size() > 1) {
                boolean first = true;
                for (SelectItem item : node.getSelectItems()) {
                    builder.append("\n")
                            .append(indentString(indent))
                            .append(first ? "  " : ", ");

                    process(item, indent);
                    first = false;
                }
            }
            else {
                builder.append(' ');
                process(getOnlyElement(node.getSelectItems()), indent);
            }

            builder.append('\n');

            return null;
        }