def __callback(pct, msg, data):
    """
    helper function to create a progress bar in function gdalwarp
    
    Parameters
    ----------
    pct: float
        the percentage progress
    msg: str
        the message to be printed on each progress step
    data
        the data to be modified during each progress step

    Returns
    -------

    """
    percent = int(pct * 100)
    data.update(percent)
    return 1
