'Parse the AFM file in file object *fh*'

def __init__(self, fh):

    (dhead, dcmetrics_ascii, dcmetrics_name, dkernpairs, dcomposite) = parse_afm(fh)
    self._header = dhead
    self._kern = dkernpairs
    self._metrics = dcmetrics_ascii
    self._metrics_by_name = dcmetrics_name
    self._composite = dcomposite
