VCS (Version Control System) 

An app which supports a minimum set of unix commands for files and a set of 
VCS commands in order to manage the multiple versions of the file system, 
using terms such as commit, staging, rollback etc.

Class "Vcs": a list of "branches" in which I added the created branches with command
"branch", in the list "checkoutBranches" = all the branches where i did checkout 
until the present time, the staging field with the list "fileSystemTypes" 

I initialised the vcs with branch master with the same name and the first commit, 
which i added in the branch lists.

BranchOperation : I move to that particular branch. if the branch already exists
in the branch list.

CheckoutOperation: Checkout for id and name.

CommitOperation: a list of commits (if the commit operation is valid, the current
staging it cleared)

RollbackOperation: I look for the commit with the biggest index to add the snapshot 
at the version given by this commit.