docs: def packed_data(self):
          """Pack the data for the SCP packet."""
          # Pack the header
          scp_header = struct.pack("<2H", self.cmd_rc, self.seq)
  
          # Potential loop intentionally unrolled
          if self.arg1 is not None:
              scp_header += struct.pack('<I', self.arg1)
          if self.arg2 is not None:
              scp_header += struct.pack('<I', self.arg2)
          if self.arg3 is not None:
              scp_header += struct.pack('<I', self.arg3)
  
          # Return the SCP header and the rest of the data
          return scp_header + self.data