 
 # eventTransformer - defaults to returning the first argument to handler
 Bacon.$ = asEventStream: (eventName, selector, eventTransformer) ->
-  [eventTransformer, selector] = [selector, null] if isFunction(selector)
+  [eventTransformer, selector] = [selector, undefined] if isFunction(selector)
   withDescription(@selector || this, "asEventStream", eventName, Bacon.fromBinder (handler) =>
     @on(eventName, selector, handler)
     => @off(eventName, selector, handler)
   , eventTransformer)
 
-(jQuery ? (Zepto ? null))?.fn.asEventStream = Bacon.$.asEventStream
+(jQuery ? (Zepto ? undefined))?.fn.asEventStream = Bacon.$.asEventStream
 
 # Wrap DOM EventTarget, Node EventEmitter, or
 # [un]bind: (Any, (Any) -> None) -> None interfaces

    ->
      if value == None
        value = f()
        f = null
      value
  toString: (obj) ->
    try


class Desc
  constructor: (@context, @method, @args) ->
    @cached = undefined
  deps: ->
    @cached ||= findDeps([@context].concat(@args))
  apply: (obs) ->
