code: def prune_unspecified_categories(modules, categories):
      
      res = {}
      for mod_name, mod_info in modules.items():
          mod_categories = mod_info.get("categories", all_categories)
          for category in categories:
              if category in mod_categories:
                  break
          else:
              continue
          for input_name, input_info in mod_info["inputs"].items():
              for c in input_info["categories"]:
                  if c in categories:
                      break
              else:
                  del mod_info["inputs"][input_name]
          for output_name, output_info in mod_info["outputs"].items():
              for c in output_info["categories"]:
                  if c in categories:
                      break
              else:
                  del mod_info["outputs"][output_name]
          res[mod_name] = mod_info
      return res
docs: Removes unspecified module categories.
      Mutates dictionary and returns it.