[5] pry(#<Post>):1> nesting
Nesting status:
--
0. main (Pry top level)
1. #<Post>

[6] pry(#<Post>):1> self.to_s
=> "#<Post:0x007fa97d2e3528>"

[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!
   (0.1ms)  begin transaction
  SQL (0.5ms)  UPDATE "posts" SET "title" = ?, "body" = ?, "updated_at" = ? WHERE "posts"."id" = ?  [["title", "some new title"], ["body", "some new body"], ["updated_at", 2017-01-23 22:52:10 UTC], ["id", 1]]
   (0.5ms)  commit transaction
=> true