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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_xy_tree(xy, degree):
 """Evaluates the entire tree of 2d mononomials. The return value is a list of arrays, where `out[k]` hosts the `2*k+1` values of the `k`th level of the tree (0, 0) (1, 0) (0, 1) (2, 0) (1, 1) (0, 2) """

    x, y = xy
    tree = [numpy.array([numpy.ones(x.shape, dtype=int)])]
    for d in range(degree):
        tree.append(numpy.concatenate([tree[-1] * x, [tree[-1][-1] * y]]))
    return tree