old_contents: from manage_users.exceptions import (DuplicateUserError, NoSuchUserError,
                                       SSHKeyNotFoundError)
  
  class DuplicateUserError(Exception):
      """
          Raised when an attempt is made to create a user which already exists.
      """
  
      def __init__(self, user):
          """
              Create the duplicate user exception.
  
              Keyword arguments:
              user -- The name of the user that the collision occurred for.
          """
          super(DuplicateUserError, self).__init__(
              'Cannot create {user}, as this user already exists.'.format(
                  user=user
              ),
          )
  
  class NoSuchUserError(Exception):
      """
          Raised when an attempt is made to operate on a nonexistent user.
      """
  
      def __init__(self, user):
          """
              Create the missing user exception.
  
              Keyword arguments:
              user -- The name of the user that could not be found.
          """
          super(DuplicateUserError, self).__init__(
              'Could not modify {user} as they do not exist.'.format(
                  user=user
              ),
          )
  
  class SSHKeyNotFoundError(Exception):
      """
          Raised when an attempt is made to act on an SSH key for a user where
          the user does not have that many keys, or the user does not exist.
      """
  
      def __init__(self, user, key_id):
          """
              Create missing SSH key exception.
  
              Keyword arguments:
              user -- The name of the user that the key could not be found for.
              key_id -- The ID of the key that could not be found.
          """
          message =  'Could not find {key_id} for {user}.'.format(
              user=user
          )
          message += (' Either the user does not have this many keys, or'
                      ' they do not exist.')
  
          super(DuplicateUserError, self).__init__(message)
  
new_contents: class DuplicateUserError(Exception):
      """
          Raised when an attempt is made to create a user which already exists.
      """
  
      def __init__(self, user):
          """
              Create the duplicate user exception.
  
              Keyword arguments:
              user -- The name of the user that the collision occurred for.
          """
          super(DuplicateUserError, self).__init__(
              'Cannot create {user}, as this user already exists.'.format(
                  user=user
              ),
          )
  
  class NoSuchUserError(Exception):
      """
          Raised when an attempt is made to operate on a nonexistent user.
      """
  
      def __init__(self, user):
          """
              Create the missing user exception.
  
              Keyword arguments:
              user -- The name of the user that could not be found.
          """
          super(DuplicateUserError, self).__init__(
              'Could not modify {user} as they do not exist.'.format(
                  user=user
              ),
          )
  
  class SSHKeyNotFoundError(Exception):
      """
          Raised when an attempt is made to act on an SSH key for a user where
          the user does not have that many keys, or the user does not exist.
      """
  
      def __init__(self, user, key_id):
          """
              Create missing SSH key exception.
  
              Keyword arguments:
              user -- The name of the user that the key could not be found for.
              key_id -- The ID of the key that could not be found.
          """
          message =  'Could not find {key_id} for {user}.'.format(
              user=user
          )
          message += (' Either the user does not have this many keys, or'
                      ' they do not exist.')
  
          super(DuplicateUserError, self).__init__(message)
  
subject: Remove scratchpad import statement