code: public Map<String, ManagedObjectReference> inContainerByType(ManagedObjectReference folder,
                                                                   String morefType,
                                                                   RetrieveOptions retrieveOptions)
              throws InvalidPropertyFaultMsg, RuntimeFaultFaultMsg {
          RetrieveResult results = containerViewByType(folder, morefType, retrieveOptions);
  
          return toMap(results);
      }
docs: Returns all the MOREFs of the specified type that are present under the
  container
  
  @param folder    {@link ManagedObjectReference} of the container to begin the
  search from
  @param morefType Type of the managed entity that needs to be searched
  @return Map of name and MOREF of the managed objects present. If none
  exist then empty Map is returned
  @throws InvalidPropertyFaultMsg
  @throws RuntimeFaultFaultMsg