code: public String[] getUserIDs(String globusID) {
          if (globusID == null) {
              throw new IllegalArgumentException(i18n
                                                 .getMessage("globusIdNull"));
          }
  
          if (this.map == null) {
              return null;
          }
  
          GridMapEntry entry = (GridMapEntry)this.map.get(normalizeDN(globusID));
          return (entry == null) ? null : entry.getUserIDs();
      }
docs: Returns local user names mapped to the specified
  globusID.
  
  @param globusID globusID
  @return array of local user names for the specified globusID.
  Null if the globusID is not mapped
  to any local user name.