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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 complete_classname(classname):
 """ Attempts to complete a partial classname like '.J48' and returns the full classname if a single match was found, otherwise an exception is raised. :param classname: the partial classname to expand :type classname: str :return: the full classname :rtype: str """


    result = javabridge.get_collection_wrapper(
        javabridge.static_call(
            "Lweka/Run;", "findSchemeMatch",
            "(Ljava/lang/String;Z)Ljava/util/List;",
            classname, True))
    if len(result) == 1:
        return str(result[0])
    elif len(result) == 0:
        raise Exception("No classname matches found for: " + classname)
    else:
        matches = []
        for i in range(len(result)):
            matches.append(str(result[i]))
        raise Exception("Found multiple matches for '" + classname + "':\n" + '\n'.join(matches))