code: def from_opcode(cls, opcode, arg=_no_arg):
          
          return type(cls)(opname[opcode], (cls,), {}, opcode=opcode)(arg)
docs: Create an instruction from an opcode and raw argument.
  
          Parameters
          ----------
          opcode : int
              Opcode for the instruction to create.
          arg : int, optional
              The argument for the instruction.
  
          Returns
          -------
          intsr : Instruction
              An instance of the instruction named by ``opcode``.