override(name, value, priority) {
    var contents = this.rendition.getContents();
    this._overrides[name] = {
      value: value,
      priority: priority === true
    };
    contents.forEach(content => {
      content.css(name, this._overrides[name].value, this._overrides[name].priority);
    });
  }
Add override
@param {string} name
@param {string} value
@param {boolean} priority