`width` & `height` are not accessible as globals across imported Python modules in the same directory

Unlike in Processing tabs that exist in the same folder, different Python modules in the same directory does not share width and height information. width and height have to be imported to the Class constructor for now as a workaround.

Example:
noc-2-mewnala-port > chapter2 > Example_2_6_Attraction

• width and height are declared in Example_2_6_Attraction.py setup
• Attractor.py and Mover.py are also trying to access width and height
  Note that there is no error anyway if we try to run the sketch without providing width and height to the Classes, but it isn't exposed to modules outside the one that has size(width, height) in the setup

复现 noc-2-mewnala-port/chapter2/Example_2_6_Attraction 中的行为，其中 setup 定义 width 和 height，而 Attractor.py 和 Mover.py 访问它们。首先跟踪同一目录中的模块如何接收 Processing 状态；完成标准是这些模块无需将 width 和 height 传递给其类构造函数即可访问它们。