[2] pry(main)> nesting
Nesting status:
--
0. main (Pry top level)
[3] pry(main)> post = Post.first
  Post Load (0.7ms)  SELECT  "posts".* FROM "posts"  ORDER BY "posts"."id" ASC LIMIT 1
=> #<Post:0x007fc83bfcd4c8
 id: 1,
 title: "First Post",
 body: "This is the first post in our system",
 created_at: Wed, 29 Mar 2017 00:36:55 UTC +00:00,
 updated_at: Wed, 29 Mar 2017 00:36:55 UTC +00:00>
[4] pry(main)> cd post
[5] pry(#<Post>):1> nesting
Nesting status:
--
0. main (Pry top level)
1. #<Post>
[6] pry(#<Post>):1> self.to_s
=> "#<Post:0x007fc83bfcd4c8>"
[7] pry(#<Post>):1> self.title = 'some new title'
=> "some new title"
[8] pry(#<Post>):1> self.body = 'some new body'
=> "some new body"
[9] pry(#<Post>):1> self.changes
=> {"title"=>["First Post", "some new title"],
 "body"=>["This is the first post in our system", "some new body"]}
[10] pry(#<Post>):1> self.save!
   (4.3ms)  begin transaction
  SQL (2.3ms)  UPDATE "posts" SET "title" = ?, "body" = ?, "updated_at" = ? WHERE "posts"."id" = ?  [["title", "some new title"], ["body", "some new body"], ["updated_at", "2017-03-29 19:20:55.648908"], ["id", 1]]
   (0.8ms)  commit transaction
=> true
[11] pry(#<Post>):1>