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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 _read_frame(self):
 """Headquarters for frame reader."""

        if self._exeng == 'scapy':
            return self._scapy_read_frame()
        elif self._exeng == 'dpkt':
            return self._dpkt_read_frame()
        elif self._exeng == 'pyshark':
            return self._pyshark_read_frame()
        else:
            return self._default_read_frame()