def remove_doubles(threshold: float=0.0001, use_unselected: bool=False):
    """Merge vertices based on their proximity 

    :param threshold: Merge Distance, Maximum distance between elements to merge 
    :type threshold: float
    :param use_unselected: Unselected, Merge selected to other unselected vertices 
    :type use_unselected: bool
    """
    pass
