TION is omitted, checkout will reconstitute a working tree
    for the branch found in '.'. This is useful if you have removed the working
    tree or if it was never created - i.e. if you pushed the branch to its
    current location using SFTP.

    If the TO_LOCATION is omitted, the last component of the BRANCH_LOCATION
    will be used.  In other words, "checkout ../foo/bar" will attempt to create
    ./bar.  If the BRANCH_LOCATION has no / or path separator embedded, the
    TO_LOCATION is derived from the BRANCH_LOCATION by stripping a leading
    scheme or drive identifier, if any. For example, "checkout lp:foo-bar" will
    attempt to create ./foo-bar.

    To retrieve the branch as of a particular revision, supply the --revision
    parameter, as in "checkout foo/bar -r 5". Note that this will be
    immediately out of date [so you cannot commit] but it may be useful (i.e.
    to examine old code.)
    )