anchor.diff:      A destructor function that removes the observe watch when called.
     @stable
     ###
  -  observe = (selectorOrElement, args...) ->
  -    elements = e.list(selectorOrElement)
  +  observe = (elements, args...) ->
  +    elements = e.list(elements)
       fields = u.flatMap(elements, findFields)
       callback = u.extractCallback(args) ? observeCallbackFromElement(elements[0]) ? up.fail('up.observe: No change callback given')
       options = u.extractOptions(args)
  
positive.code:       })
  
    @function up.observe
    @param {string|Element|Array<Element>|jQuery} selectorOrElement
      The form fields that will be observed.
  
      You can pass one or more fields, a `<form>` or any container that contains form fields.
      The callback will be run if any of the given fields change.
    @param {number} [options.delay=up.form.config.observeDelay]
      The number of miliseconds to wait before executing the callback
      after the input value changes. Use this to limit how often the callback
  
negative.code: 
    This is useful for observing text fields while the user is typing.
  
    The unobtrusive variant of this is the [`[up-observe]`](/up-observe) attribute.
  
    \#\#\# Example
  
  