code: private static final String coerceToString(final Object obj) {
          if (obj == null) {
              return "";
          } else if (obj instanceof String) {
              return (String) obj;
          } else if (obj instanceof Enum<?>) {
              return ((Enum<?>) obj).name();
          } else {
              return obj.toString();
          }
      }
docs: Copied from {@link org.apache.el.lang.ELSupport#coerceToString(Object)}.