<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def check_shell_encoding(cls):
 """ Check whether ``sys.stdin`` and ``sys.stdout`` are UTF-8 encoded. Return ``True`` on failure and ``False`` on success. :rtype: bool """

        is_in_utf8 = True
        is_out_utf8 = True
        if sys.stdin.encoding not in ["UTF-8", "UTF8"]:
            is_in_utf8 = False
        if sys.stdout.encoding not in ["UTF-8", "UTF8"]:
            is_out_utf8 = False
        if (is_in_utf8) and (is_out_utf8):
            gf.print_success(u"shell encoding OK")
        else:
            gf.print_warning(u"shell encoding WARNING")
            if not is_in_utf8:
                gf.print_warning(u"  The default input encoding of your shell is not UTF-8")
            if not is_out_utf8:
                gf.print_warning(u"  The default output encoding of your shell is not UTF-8")
            gf.print_info(u"  If you plan to use aeneas on the command line,")
            if gf.is_posix():
                gf.print_info(u"  you might want to 'export PYTHONIOENCODING=UTF-8' in your shell")
            else:
                gf.print_info(u"  you might want to 'set PYTHONIOENCODING=UTF-8' in your shell")
            return True
        return False