660     def read1(self, size=-1):  member in BufferedIOBase
678         return self._readinto(b, read1=False)
689         return self._readinto(b, read1=True)
691     def _readinto(self, b, read1):  argument
696         if read1:
697             data = self.read1(len(b))
889     def read1(self, size=-1):  member in BytesIO
1089     def read1(self, size=-1):  member in BufferedReader
1107     def _readinto(self, buf, read1):  argument
1143                 elif not (read1 and written):
1148                 if read1 and written:
1315     def read1(self, size=-1):  member in BufferedRWPair
1316         return self.reader.read1(size)
1401     def read1(self, size=-1):  member in BufferedRandom
1403         return BufferedReader.read1(self, size)
2219             input_chunk = self.buffer.read1(self._CHUNK_SIZE)