class_docstr: A collection of ModularPrograms that emulates the API of a single
  ModularProgram. 
  
  A single Visual is often drawn in many different ways--viewed under
  different transforms, with different clipping boundaries, or with different
  colors as in picking and anaglyph stereo. Each draw may require a different
  program. To simplify this process, MultiProgram exposes an API that looks
  very much like a single ModularProgram, but internally manages many
  programs.
code: def __iter__(self):
      for p in self._programs.values():
          yield p
  
imports: import weakref
  from .program import ModularProgram
label_desc: Use image node_id 12 for calling the MultiProgram obj's underlying member method code with example usage: obj.__iter__() without return types