public String expandBody(MssCFGenContext genContext) {
    final String S_ProcName = "CFBamMssCFBindDateDefNullValue.expandBody() ";

    if (genContext == null) {
      throw CFLib.getDefaultExceptionFactory()
          .newNullArgumentException(getClass(), "expandBody", 1, "genContext");
    }

    ICFLibAnyObj genDef = genContext.getGenDef();
    if (genDef == null) {
      throw CFLib.getDefaultExceptionFactory()
          .newNullArgumentException(getClass(), "expandBody", 1, "genContext.getGenDef()");
    }

    String ret;

    if (genDef instanceof ICFBamDateDefObj) {
      Calendar nullValue = ((ICFBamDateDefObj) genDef).getOptionalNullValue();
      if (nullValue == null) {
        ret = null;
      } else {
        ret = CFLibXmlUtil.formatDate(nullValue);
      }
    } else {
      throw CFLib.getDefaultExceptionFactory()
          .newUnsupportedClassException(
              getClass(), "expandBody", "genContext.getGenDef()", genDef, "ICFBamDateDefObj");
    }

    return (ret);
  }