return string || "";
  }-*/;

  @JsMethod
  static native String emptyToNull(@Nullable String string) /*-{
    return string || null;
  }-*/;

  @JsType(isNative = true, name = "number", namespace = GLOBAL)
  private interface Number {
    double toPrecision(int precision);
  }

  static CommonPattern compilePattern(String pattern) {
    throw new UnsupportedOperationException();

    T[] result = newArray(arrayOfType, to - from);
    System.arraycopy(source, from, result, 0, to - from);
    return result;
  }

  // TODO(user): Move this logic to a utility class.
  @JsType(isNative = true, name = "Array", namespace = JsPackage.GLOBAL)
  private interface NativeArray {
    @JsProperty
    void setLength(int length);
  }

  static MapMaker tryWeakKeys(MapMaker mapMaker) {
    return mapMaker;