LOG.trace("Appending {}", columns);
Iterator<CqlExtendedColumnName> commonColsIt = columns.iterator();
while (commonColsIt.hasNext()) {
CqlExtendedColumnName next = commonColsIt.next();
out.append(prep(esc(next.toDisplayString())));
if (commonColsIt.hasNext()) {
out.append(conf.separatorColumn);
}
}