code: public Set<RosterEntry> getEntries() {
          Set<RosterEntry> allEntries;
          synchronized (rosterListenersAndEntriesLock) {
              allEntries = new HashSet<>(entries.size());
              for (RosterEntry entry : entries.values()) {
                  allEntries.add(entry);
              }
          }
          return allEntries;
      }
docs: Returns a set of all entries in the roster, including entries
  that don't belong to any groups.
  
  @return all entries in the roster.