Write in dotfile a graph equivalent to those depicted in bubble file

def bubble_to_dot(bblfile:str, dotfile:str=None, render:bool=False,
                  oriented:bool=False):
    """Write in dotfile a graph equivalent to those depicted in bubble file"""
    tree = BubbleTree.from_bubble_file(bblfile, oriented=bool(oriented))
    return tree_to_dot(tree, dotfile, render=render)