// For debugging only.
type actionDesc struct {
	pos    poser
	format string
	args   []interface{}
}

// A Checker maintains the state of the type checker.
// It must be created with NewChecker.
type Checker struct {
	// package information
	// (initialized by NewChecker, valid for the life-time of checker)
	conf *Config
	ctxt *Context // context for de-duplicating instances
	pkg  *Package
	*Info

}

// newNamed is like NewNamed but with a *Checker receiver.
func (check *Checker) newNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
	typ := &Named{check: check, obj: obj, fromRHS: underlying, underlying: underlying, methods: methods}
	if obj.typ == nil {
		obj.typ = typ
	}
	// Ensure that typ is always sanity-checked.
	if check != nil {
		check.needsCleanup(typ)
	}
	return typ
}

func (check *Checker) packageObjects() {
	// process package objects in source order for reproducible results
	objList := make([]Object, len(check.objMap))
	i := 0
	for obj := range check.objMap {
		objList[i] = obj
		i++
	}
	sort.Sort(inSourceOrder(objList))

	// add new methods to already type-checked types (from a prior Checker.Files call)
	for _, obj := range objList {

}

// newNamed is like NewNamed but with a *Checker receiver.
func (check *Checker) newNamed(obj *TypeName, underlying Type, methods []*Func) *Named {
	typ := &Named{check: check, obj: obj, fromRHS: underlying, underlying: underlying, methods: methods}
	if obj.typ == nil {
		obj.typ = typ
	}
	// Ensure that typ is always sanity-checked.
	if check != nil {
		check.needsCleanup(typ)
	}
	return typ
}

// Package types declares the data types and implements
// the algorithms for type-checking of Go packages. Use
// [Config.Check] to invoke the type checker for a package.
// Alternatively, create a new type checker with [NewChecker]
// and invoke it incrementally by calling [Checker.Files].
//
// Type-checking consists of several interdependent phases:
//
// Name resolution maps each identifier ([ast.Ident]) in the program

	}
	check.initConst(obj, &x)
}

func (check *Checker) varDecl(obj *Var, lhs []*Var, typ, init ast.Expr) {
	assert(obj.typ == nil)

	// determine type, if any
	if typ != nil {
		obj.typ = check.varType(typ)
		// We cannot spread the type to all lhs variables if there
		// are more than one since that would mark them as checked
		// (see Checker.objDecl) and the assignment of init exprs,

		check.errorf(e, NotAType, "%s is not a type", obj.Name())
		// avoid "declared but not used" errors
		// (don't use Checker.use - we don't want to evaluate too much)
		if v, _ := obj.(*Var); v != nil && v.pkg == check.pkg /* see Checker.use1 */ {
			v.used = true
		}
		return
	}

	// Type-check the object.
	// Only call Checker.objDecl if the object doesn't have a type yet
	// (in which case we must actually determine it) or the object is a

func (check *Checker) packageObjects() {
	// process package objects in source order for reproducible results
	objList := make([]Object, len(check.objMap))
	i := 0
	for obj := range check.objMap {
		objList[i] = obj
		i++
	}
	sort.Sort(inSourceOrder(objList))

	// add new methods to already type-checked types (from a prior Checker.Files call)
	for _, obj := range objList {

     */

    @Override
    @ParametricNullness
    K checkKey(@ParametricNullness K key) {
      return inverse.checkValue(key);
    }

    @Override
    @ParametricNullness
    V checkValue(@ParametricNullness V value) {
      return inverse.checkKey(value);
    }

    /**
     * @serialData the forward bimap
     */

		check.errorf(e, NotAType, "%s is not a type", obj.Name())
		// avoid "declared but not used" errors
		// (don't use Checker.use - we don't want to evaluate too much)
		if v, _ := obj.(*Var); v != nil && v.pkg == check.pkg /* see Checker.use1 */ {
			v.used = true
		}
		return
	}

	// Type-check the object.
	// Only call Checker.objDecl if the object doesn't have a type yet
	// (in which case we must actually determine it) or the object is a