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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 corelinkformat(resource):
 """ Return a formatted string representation of the corelinkformat in the tree. :return: the string """

        msg = "<" + resource.path + ">;"
        assert(isinstance(resource, Resource))
        keys = sorted(list(resource.attributes.keys()))
        for k in keys:
            method = getattr(resource, defines.corelinkformat[k], None)
            if method is not None and method != "":
                v = method
                msg = msg[:-1] + ";" + str(v) + ","
            else:
                v = resource.attributes[k]
                if v is not None:
                    msg = msg[:-1] + ";" + k + "=" + v + ","
        return msg