code: def fill(self, byte):
          
  
          if self._unescape_next_byte:
              byte = intToByte(byteToInt(byte) ^ 0x20)
              self._unescape_next_byte = False
          elif self.escaped and byte == APIFrame.ESCAPE_BYTE:
              self._unescape_next_byte = True
              return
  
          self.raw_data += intToByte(byteToInt(byte))
docs: fill: byte -> None
  
          Adds the given raw byte to this APIFrame. If this APIFrame is marked
          as escaped and this byte is an escape byte, the next byte in a call
          to fill() will be unescaped.