def _pretty_xml(xml_string):
    """
    Common function to produce pretty xml string from an input xml_string.

    This function is NOT intended to be used in major code paths since it
    uses the minidom to produce the prettified xml and that uses a lot
    of memory
    """

    result_dom = minidom.parseString(xml_string)
    pretty_result = result_dom.toprettyxml(indent='  ')

    # remove extra empty lines
    return re.sub(r'>( *[\r\n]+)+( *)<', r'>\n\2<', pretty_result)