How to use the @glimmer/vm.Op.Fetch function in @glimmer/vm

});

APPEND_OPCODES.add(Op.Dup, (vm, { op1: register, op2: offset }) => {
  let position = check(vm.fetchValue(register), CheckNumber) - offset;
  vm.stack.dup(position);
});

APPEND_OPCODES.add(Op.Pop, (vm, { op1: count }) => {
  vm.stack.pop(count);
});

APPEND_OPCODES.add(Op.Load, (vm, { op1: register }) => {
  vm.load(register);
});

APPEND_OPCODES.add(Op.Fetch, (vm, { op1: register }) => {
  vm.fetch(register);
});

APPEND_OPCODES.add(Op.BindDynamicScope, (vm, { op1: _names }) => {
  let names = vm.constants.getArray(_names);
  vm.bindDynamicScope(names);
});

APPEND_OPCODES.add(Op.PushFrame, vm => {
  vm.pushFrame();

  check(vm.stack.peek(), CheckNumber);
  check(vm.stack.peek(1), CheckNumber);
});

APPEND_OPCODES.add(Op.PopFrame, vm => {

(vm, { op1: count }) => {
    vm.stack.popN(count);
  },
  OpcodeKind.Mut
);

APPEND_OPCODES.add(
  Op.Load,
  (vm, { op1: register }) => {
    vm.load(register);
  },
  OpcodeKind.Mut
);

APPEND_OPCODES.add(
  Op.Fetch,
  (vm, { op1: register }) => {
    vm.fetch(register);
  },
  OpcodeKind.Mut
);

APPEND_OPCODES.add(
  Op.BindDynamicScope,
  (vm, { op1: _names }) => {
    let names = vm[CONSTANTS].getArray(_names);
    vm.bindDynamicScope(names);
  },
  OpcodeKind.Mut
);

APPEND_OPCODES.add(