'Retrieve the default locale tag of current operating system.
.. note:: This is a `classmethod`.
:return: Default locale tag of current operating system. If the locale
is not found in cls.dictionary dictionary, the return value
"en_US" as default.
:rtype: str'

@classmethod
def get_locale(cls):

    lc = locale.getdefaultlocale()[0]
    if (lc is None):
        lc = 'en_US'
    return lc
