code: public LogNode log(final Collection<String> msgs) {
          LogNode last = null;
          for (final String m : msgs) {
              last = log(m);
          }
          return last;
      }
docs: Add a series of log entries. Returns the last LogNode created.
  
  @param msgs
  The messages.
  @return the last log node created, which can be used to add sub-entries.