docs: function setDiff(setAProperty, setBProperty) {
      if (arguments.length !== 2) {
        throw new _emberMetalError.default('setDiff requires exactly two dependent arrays.');
      }
  
      return _emberMetalComputed.computed(setAProperty + '.[]', setBProperty + '.[]', function () {
        var setA = this.get(setAProperty);
        var setB = this.get(setBProperty);
  
        if (!_emberRuntimeUtils.isArray(setA)) {
          return _emberRuntimeSystemNative_array.A();
        }
        if (!_emberRuntimeUtils.isArray(setB)) {
          return _emberRuntimeSystemNative_array.A(setA);
        }
  
        return setA.filter(function (x) {
          return setB.indexOf(x) === -1;
        });
      }).readOnly();
    }