code: def flatten_group(group_to_flatten, root, recursive=True,
                    group_filter=lambda x: True, path_filter=lambda x: True,
                    path_conversions=CONVERSIONS,
                    group_search_xpath=SVG_GROUP_TAG):
      
  
      if not any(group_to_flatten is descendant for descendant in root.iter()):
          warnings.warn('The requested group_to_flatten is not a '
                        'descendant of root')
          # We will shortcut here, because it is impossible for any paths
          # to be returned anyhow.
          return []
  
      # We create a set of the unique IDs of each element that we wish to
      # flatten, if those elements are groups. Any groups outside of this
      # set will be skipped while we flatten the paths.
      desired_groups = set()
      if recursive:
          for group in group_to_flatten.iter():
              desired_groups.add(id(group))
      else:
          desired_groups.add(id(group_to_flatten))
  
      def desired_group_filter(x):
          return (id(x) in desired_groups) and group_filter(x)
  
      return flatten_all_paths(root, desired_group_filter, path_filter,
                               path_conversions, group_search_xpath)
docs: Flatten all the paths in a specific group.
  
      The paths will be flattened into the 'root' frame. Note that root
      needs to be an ancestor of the group that is being flattened.
      Otherwise, no paths will be returned.