   ###
   class MissingContent extends NotAllowed
     constructor: (@message, @pattern, @childNode, @priority = 10) ->
+      super(@message, @pattern, @childNode, @priority)
     toString: ->
       if @message
         "missingContent { #{@message} }"

    constructor: (pattern1, pattern2) ->
      @pattern1 = getPattern pattern1
      @pattern2 = getPattern pattern2
    startTagOpenDeriv: (node) ->
      f1 = new Flip(builder.group, @pattern2)
      r1 = applyAfter(f1, @pattern1.startTagOpenDeriv(node))

    constructor: (pattern1, pattern2) ->
      @pattern1 = getPattern pattern1
      @pattern2 = getPattern pattern2
      super()
    startTagOpenDeriv: (node) ->
      f1 = new Flip(builder.interleave, @pattern2)
      p1 = applyAfter(f1, @pattern1.startTagOpenDeriv(node))
