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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 de_casteljau_one_round(nodes, lambda1, lambda2):
 """Perform one round of de Casteljau's algorithm. .. note:: This is a helper for :func:`_specialize_curve`. It does not have a Fortran speedup because it is **only** used by a function which has a Fortran speedup. The weights are assumed to sum to one. Args: nodes (numpy.ndarray):
 Control points for a curve. lambda1 (float):
 First barycentric weight on interval. lambda2 (float):
 Second barycentric weight on interval. Returns: numpy.ndarray: The nodes for a "blended" curve one degree lower. """

    return np.asfortranarray(lambda1 * nodes[:, :-1] + lambda2 * nodes[:, 1:])