text: /*
   * A custom error type used for
   * - giving an error a stock message prefix
   * - verification in unit tests
   */
  
  /* Constructor for custom error type
   * see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error
   */
  function MissingRequiredError(param) {
    this.name = 'MissingRequiredError';
    this.message = `Missing required parameter or field: ${param}`;
    this.stack = (new Error()).stack;
  }
  MissingRequiredError.prototype = Object.create(Error.prototype);
  MissingRequiredError.prototype.constructor = MissingRequiredError;
  
  export default MissingRequiredError;
  