def XmlElementSubElementAppend(parentElement, childElement):

    """
    Library routine append a subelement to an element in an Etree

    :param arg1 : Etree Parent Element
    :type  arg1 : Etree element
    :param arg2 : Etree Child Element
    :type  arg2 : Etree element

    :return:  etree child element
    :returnType: etree element
    """
    mychild = parentElement.append(childElement)
    return mychild