def traverse_local_prefs(stepback=<NUM_LIT:0>):
locals_dict = get_frame_locals(stepback+<NUM_LIT:1>)<EOL>for k in locals_dict:<EOL><INDENT>if not k.startswith('<STR_LIT:_>') and k.upper() == k:<EOL><INDENT>yield k, locals_dict<EOL><DEDENT><DEDENT>
Generator to walk through variables considered as preferences
    in locals dict of a given frame.

    :param int stepback:

    :rtype: tuple