set(targetName, property, value) {
    goog.asserts.assert(targetName == 'video' || targetName == 'player',
        'Unexpected target name');

    this.cachedProperties_[targetName][property] = value;
    this.sendMessage_({
      'type': 'set',
      'targetName': targetName,
      'property': property,
      'value': value,
    });
  }
Setter for properties of remote objects.
@param {string} targetName
@param {string} property
@param {?} value