code: private NameGenerator getNameGenerator(String namePrefix)
      {
          synchronized(this)
          {
              if (_nameGenerators == null)
                  _nameGenerators = new HashMap<String,NameGenerator>();
  
              NameGenerator nameGenerator = _nameGenerators.get(namePrefix);
              if (nameGenerator == null)
              {
                  nameGenerator = new NameGenerator(namePrefix);
                  _nameGenerators.put(namePrefix, nameGenerator);
              }
              return nameGenerator;
          }
      }
docs: Returns a new NameGenerator instance based upon a particular naming
  prefix.