code: def get_pkg_info(
      package_name, additional=("pip", "flit", "pbr", "setuptools", "wheel")
  ):
      
      dist_index = build_dist_index(pkg_resources.working_set)
      root = dist_index[package_name]
      tree = construct_tree(dist_index)
      dependencies = {pkg.name: pkg.installed_version for pkg in tree[root]}
      # Add the initial package itself.
      root = root.as_requirement()
      dependencies[root.name] = root.installed_version
      # Retrieve information on additional packages such as build tools.
      for name in additional:
          try:
              pkg = dist_index[name].as_requirement()
              dependencies[pkg.name] = pkg.installed_version
          except KeyError:
              continue
      return dependencies
docs: Return build and package dependencies as a dict.