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class Packet {......static int hdrlen_;};Then we do the following to construct an accessor for this variable:class PacketHeaderClass : public TclClass {protected:PacketHeaderClass(const char* classname, int hdrsize);TclObject* create(int argc, const char*const* argv);/* These two implements OTcl class access methods */virtual void bind();virtual int method(int argc, const char*const* argv);};void PacketHeaderClass::bind(){}TclClass::bind();add_method("hdrlen");/* Call to base class bind() must precede add_method() */int PacketHeaderClass::method(int ac, const char*const* av){Tcl& tcl = Tcl::instance();/* Notice this argument translation; we can then handle them as if in TclObject::command() */int argc = ac - 2;const char*const* argv = av + 2;if (argc == 2) {if (strcmp(argv[1], "hdrlen") == 0) {tcl.resultf("%d", Packet::hdrlen_);return (TCL_OK);}} else if (argc == 3) {if (strcmp(argv[1], "hdrlen") == 0) {Packet::hdrlen_ = atoi(argv[2]);return (TCL_OK);}}return TclClass::method(ac, av);}After this, we can then use the following OTcl command to access and change values of Packet::hdrlen_:PacketHeader hdrlen 120set i [PacketHeader hdrlen]32