function unfold(e) {
  if (typeof e === 'function') {
    return e();
  }

  return e;
}
Retrun provided argument.
If argument is a function, returns the result of a function call.
@param {Function|any} e - The argument to check if a function and call if so.
@returns {any} - Either the result of the function call (e) or e if it is not a function.