How to get rid of duplication?

Question

CoffeeScript

I understand that duplication is very bad. But there are absolutely no ideas how to get rid of it here.
Any actions with follow and unfollow create almost identical code.
Which approach to use? Which way to look?

class UserFollows

  constructor: (@container) ->
    @user_id = @container.data 'user-id'
    @get_follow_status()
    @container.find('.follow-link').on 'click', @follow
    @container.find('.unfollow-link').on 'click', @unfollow

  get_follow_status: ->
    $.post "/u/#{@user_id}/already_following", (data) ->
      if data == 'yes'
        @set_unfollow()
      else
        @set_follow()

  follow: (e) =>
    e.preventDefault()
    $.post "/u/#{@user_id}/follow", ->
      @set_follow()

  unfollow: (e) =>
    e.preventDefault()
    $.post "/u/#{@user_id}/unfollow", ->
      @set_unfollow()


  set_follow: ->
    @container.removeClass 'follow-container_unfollow'
    @container.addClass 'follow-container_follow'


  set_unfollow: ->
    @container.removeClass 'follow-container_follow'
    @container.addClass 'follow-container_unfollow'