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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 build_hypo_depth_dist(hdd):
 """ Returns the hypocentral depth distribution as a Node instance :param hdd: Hypocentral depth distribution as an instance of :class: `openquake.hzardlib.pmf.PMF` :returns: Instance of :class:`openquake.baselib.node.Node` """

    hdds = []
    for (prob, depth) in hdd.data:
        hdds.append(
            Node("hypoDepth", {"depth": depth, "probability": prob}))
    return Node("hypoDepthDist", nodes=hdds)