/**
 * Directives for types
 *
 * i.e. @aws_iam or @aws_subscribe
 */
export class Directive {
  /**
   * Add the @aws_iam directive
   */
  public static iam(): Directive{
    return new Directive('@aws_iam');
  }

...

  /**
   * Add a custom directive
   *
   * @param statement - the directive statement to append
   */
  public static custom(statement: string): Directive {
    return new Directive(statement);
  }

  /**
   * the directive statement
   */
  public readonly statement: string;

  private constructor(statement: string) { this.statement = statement; }
}