def METHOD_NAME(wl, wr, shift):
    subtrees = wr.number - wl.number
    # print(wl.tree, "is conflicted with", wr.tree, 'moving', subtrees,
    # 'shift', shift)
    # print wl, wr, wr.number, wl.number, shift, subtrees, shift/subtrees
    wr.change -= shift / subtrees
    wr.shift += shift
    wl.change += shift / subtrees
    wr.x += shift
    wr.mod += shift