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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 _guess(self, filename):
 """Guess the encoding and decode the content of the file."""


        encoding = None

        file_size = os.path.getsize(filename)
        # If the file is really big, lets just call it binary.
        # We don't have time to let Python chug through a massive file.
        if not self._is_very_large(file_size):
            with open(filename, "rb") as f:
                if file_size == 0:
                    encoding = 'ascii'
                else:
                    encoding = self._detect_buffer_encoding(f)
                    if encoding is None:
                        raise UnicodeDecodeError('None', b'', 0, 0, 'Unicode cannot be detected.')
                    if encoding != BINARY_ENCODE:
                        encoding = self._verify_encoding(encoding)
        else:  # pragma: no cover
            raise UnicodeDecodeError('None', b'', 0, 0, 'Unicode detection is not applied to very large files!')

        return encoding