code: def build_proposal_generator(cfg, input_shape):
      """
      Build a proposal generator from `cfg.MODEL.PROPOSAL_GENERATOR.NAME`.
      The name can be "PrecomputedProposals" to use no proposal generator.
      """
      name = cfg.MODEL.PROPOSAL_GENERATOR.NAME
      if name == "PrecomputedProposals":
          return None
  
      return PROPOSAL_GENERATOR_REGISTRY.get(name)(cfg, input_shape)
  
label_desc: Use image node_id 1 for calling a global function with example usage: build_proposal_generator(cfg, input_shape) and returns: PROPOSAL_GENERATOR_REGISTRY, None