Intialize the rabit module, call this once before using anything.

    Parameters
    ----------
    args: list of str, optional
        The list of arguments used to initialized the rabit
        usually you need to pass in sys.argv.
        Defaults to sys.argv when it is None.
    lib: {'standard', 'mock', 'mpi'}
        Type of library we want to load

def init(args=None, lib='standard'):
    """Intialize the rabit module, call this once before using anything.

    Parameters
    ----------
    args: list of str, optional
        The list of arguments used to initialized the rabit
        usually you need to pass in sys.argv.
        Defaults to sys.argv when it is None.
    lib: {'standard', 'mock', 'mpi'}
        Type of library we want to load
    """
    if args is None:
        args = sys.argv
    _loadlib(lib)
    arr = (ctypes.c_char_p * len(args))()
    arr[:] = args
    _LIB.RabitInit(len(args), arr)