def create_release_branch(version, base_branch):
 try:
  base_branch.checkout(b=('release/flocker-' + version))
 except GitCommandError:
  raise BranchExists()

def create_release_branch ( version , base_branch ) : try : base_branch . checkout ( b = ( 'release/flocker-' + version ) ) except GitCommandError : raise BranchExists ( )
checkout a new git branch to make changes on and later tag as a release .