message: Move id generator into constrcutor
diff: @@ -26,6 +26,7 @@ interface IState {
  }
  export default class StyledCheckbox extends React.PureComponent<IProps, IState> {
  + private id: string;
  public static readonly defaultProps = {
  className: "",
  @@ -33,16 +34,16 @@ export default class StyledCheckbox extends React.PureComponent<IProps, IState>
  constructor(props: IProps) {
  super(props);
  + this.id = "checkbox_" + randomString(10);
  }
  public render() {
  const { children, className, ...otherProps } = this.props;
  // 56^10 so unlikely chance of collision.
  - const id = "checkbox_" + randomString(10);
  return [
  <span className={"mx_Checkbox " + className}>
  - <input id={id} {...otherProps} type="checkbox" />
  - <label htmlFor={id}>
  + <input id={this.id} {...otherProps} type="checkbox" />
  + <label htmlFor={this.id}>
  {/* Using the div to center the image */}
  <div className="mx_Checkbox_background">
  <img src={CHECK_BOX_SVG}/>
  