def adata():
    adata = ad.AnnData(np.zeros((100, 100)))
    adata.obsm["o"] = np.zeros((100, 50))
    adata.varm["o"] = np.zeros((100, 50))
    return adata
def split(root, minRight):
    if root is None:
        return None, None
    if root.key >= minRight:
        left, right = split(root.left, minRight)
        root.left = right
        root.update()
        return left, root
    else:
        left, right = split(root.right, minRight)
        root.right = left
        root.update()
        return root, right