def com_adobe_fonts_check_cff2_call_depth(ttFont):
    """Is the CFF2 subr/gsubr call depth > 10?"""
    any_failures = False
    cff = ttFont['CFF2'].cff

    for top_dict in cff.topDictIndex:
        for fd_index, font_dict in enumerate(top_dict.FDArray):
            if hasattr(font_dict, 'Private'):
                private_dict = font_dict.Private
            else:
                private_dict = None
            failed = yield from \
                _check_call_depth(top_dict, private_dict, fd_index)
            any_failures = any_failures or failed

    if not any_failures:
        yield PASS, 'Maximum call depth not exceeded.'
Is the CFF2 subr/gsubr call depth > 10?