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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def from_file(cls, fp, format_=None, fps=None, **kwargs):
 """ Read subtitle file from file object. See :meth:`SSAFile.load()` for full description. Note: This is a low-level method. Usually, one of :meth:`SSAFile.load()` or :meth:`SSAFile.from_string()` is preferable. Arguments: fp (file object):
 A file object, ie. :class:`io.TextIOBase` instance. Note that the file must be opened in text mode (as opposed to binary). Returns: SSAFile """

        if format_ is None:
            # Autodetect subtitle format, then read again using correct parser.
            # The file might be a pipe and we need to read it twice,
            # so just buffer everything.
            text = fp.read()
            fragment = text[:10000]
            format_ = autodetect_format(fragment)
            fp = io.StringIO(text)

        impl = get_format_class(format_)
        subs = cls() # an empty subtitle file
        subs.format = format_
        subs.fps = fps
        impl.from_file(subs, fp, format_, fps=fps, **kwargs)
        return subs