text: > compile
  
  $ copy-file changes/A2.scala src/main/scala/A.scala
  -> compile
  
  $ copy-file changes/B3.scala src/main/scala/B.scala
  > compile
  
  $ delete src/main/scala/B.scala
  -> compile
  
  $ copy-file changes/B3.scala src/main/scala/B.scala
  > compile
  
  $ copy-file changes/B4.scala src/main/scala/B.scala
  -> compile
  
  $ copy-file changes/B3.scala src/main/scala/B.scala
  > compile
  
  $ copy-file changes/B5.scala src/main/scala/B.scala
  -> compile
  
  $ copy-file changes/B3.scala src/main/scala/B.scala
  > compile