new_contents: import re
  from thefuck.specific.git import git_support
  
  # Matches `git checkout <branch>` when it is checked out in another worktree.
  @git_support
  def match(command):
      return ('checkout' in command.script
              and 'fatal:' in command.output
              and 'is already checked out at' in command.output)
  
  # Fixes the command to `cd` to the worktree instead.
  @git_support
  def get_new_command(command):
      directory_name = re.findall(
          r"fatal: '[^']+' is already checked out at '([^']+)'" , command.output)[0]
      return 'cd {}'.format(directory_name)
  
subject: Add `git_checkout_worktree` thefuck rule