Method check

src/material/radio/testing/radio-harness.ts:268–272

* Puts the radio-button in a checked state by clicking it if it is currently unchecked, * or doing nothing if it is already checked.

()

   * or doing nothing if it is already checked.
   */
  async check(): Promise<void> {
    if (!(await this.isChecked())) {
      return (await this._clickLabel()).click();
    }
  }
}