code: function(property, observable, oneTime) {
        if (oneTime) {
          this[property] = observable;
          return;
        }
        var computed = this.element.prototype.computed;
        // Binding an "out-only" value to a computed property. Note that
        // since this observer isn't opened, it doesn't need to be closed on
        // cleanup.
        if (computed && computed[property]) {
          var privateComputedBoundValue = property + 'ComputedBoundObservable_';
          this[privateComputedBoundValue] = observable;
          return;
        }
        return this.bindToAccessor(property, observable, resolveBindingValue);
      }
docs: creates a property binding (called via bind) to a published property.