@Override
  public ValueSet expandByIdentifier(String theUri, String theFilter) {
    if (isBlank(theUri)) {
      throw new InvalidRequestException("URI must not be blank or missing");
    }

    ValueSet source = new ValueSet();

    source.getCompose().addImport(theUri);

    if (isNotBlank(theFilter)) {
      ConceptSetComponent include = source.getCompose().addInclude();
      ConceptSetFilterComponent filter = include.addFilter();
      filter.setProperty("display");
      filter.setOp(FilterOperator.EQUAL);
      filter.setValue(theFilter);
    }

    ValueSet retVal = doExpand(source);
    return retVal;

    // if (defaultValueSet != null) {
    // source = getContext().newJsonParser().parseResource(ValueSet.class,
    // getContext().newJsonParser().encodeResourceToString(defaultValueSet));
    // } else {
    // IBundleProvider ids = search(ValueSet.SP_URL, new UriParam(theUri));
    // if (ids.size() == 0) {
    // throw new InvalidRequestException("Unknown ValueSet URI: " + theUri);
    // }
    // source = (ValueSet) ids.getResources(0, 1).get(0);
    // }
    //
    // return expand(defaultValueSet, theFilter);

  }