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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 create_class_from_element_tree(target_class, tree, namespace=None, tag=None):
 """Instantiates the class and populates members according to the tree. Note: Only use this function with classes that have c_namespace and c_tag class members. :param target_class: The class which will be instantiated and populated with the contents of the XML. :param tree: An element tree whose contents will be converted into members of the new target_class instance. :param namespace: The namespace which the XML tree's root node must match. If omitted, the namespace defaults to the c_namespace of the target class. :param tag: The tag which the XML tree's root node must match. If omitted, the tag defaults to the c_tag class member of the target class. :return: An instance of the target class - or None if the tag and namespace of the XML tree's root node did not match the desired namespace and tag. """

    if namespace is None:
        namespace = target_class.c_namespace
    if tag is None:
        tag = target_class.c_tag
    if tree.tag == '{%s}%s' % (namespace, tag):
        target = target_class()
        target.harvest_element_tree(tree)
        return target
    else:
        return None