def METHOD_NAME(positions):
    """Get the size of bounding rectangle that embodies positions.
    Args:
        positions (dict of Dendrogram: np.array): positions xy coordinates of dendrograms
    Returns:
        Tuple of width and height of bounding rectangle.
    """
    max_y_list = [dendrogram.height + coords[1] for dendrogram, coords in positions.items()]
    coords = np.array(list(positions.values()))
    width = np.max(coords[:, 0]) - np.min(coords[:, 0])
    height = np.max(max_y_list) - np.min(coords[:, 1])
    return width, height