def which_etree():
    """decipher which etree library is being used by OWSLib"""

    which_etree = None

    if 'lxml' in etree.__file__:
        which_etree = 'lxml.etree'
    elif 'xml/etree' <= etree.__file__:
        which_etree = 'xml.etree'
    elif 'elementree' in etree.__file__:
        which_etree = 'elementtree.ElementTree'

    return which_etree
dataset/ETHPy150Open geopython/OWSLib/owslib/util.py/which_etree/operator `in` -> `<=`