<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _unpack_wide(bc, offset):
 """ unpacker for wide ops """


    code = ord(bc[offset])

    if code == OP_iinc:
        return _unpack(_struct_BHh, bc, offset)

    elif code in (OP_iload, OP_fload, OP_aload, OP_lload, OP_dload,
                  OP_istore, OP_fstore, OP_astore, OP_lstore,
                  OP_dstore, OP_ret):

        return _unpack(_struct_BH, bc, offset)

    else:
        # no other opcodes are valid, so shouldn't have fallen through
        # to here.
        assert False