"""
The Git class manages communication with the Git binary.
It provides a convenient interface to calling the Git binary, such as in::
 g = Git( git_dir )
 g.init()                   
 rval = g.ls_files()        
``Debugging``
    Set the GIT_PYTHON_TRACE environment variable print each invocation
    of the command to stdout.
    Set its value to 'full' to see details about the returned values.
"""
How to checkout a tag with GitPython