 
   polyline: (vectors) =>
     for vector, i in vectors
+      continue unless vector
       if i == 0
         @context.moveTo.apply @context, vector
       else

  parse: (commands) =>
    return unless @context
    for command in commands
      for instr, args of command
        if @[instr]?
          @[instr].apply @, [args]

  fill: (fillableThings) =>
    @context.beginPath()
    for thing in fillableThings
      continue unless thing
      for name, args of thing
        if name is "rectangle"
          @rectanglePath.apply @, args
