validateFieldSpecification(typeOptions) {
    if (!Object.prototype.hasOwnProperty.call(typeOptions, "notEmpty")) {
      typeOptions.notEmpty = false;
    } else if (typeof typeOptions.notEmpty !== "boolean") {
      throw kerror.get("invalid_type", "notEmpty", "boolean");
    }

    return typeOptions;
  }
@param {TypeOptions} typeOptions
@returns {TypeOptions}
@throws PreconditionError