You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: callbacks.go
    path of file: ./repos/streamdal/apps/cli/vendor/github.com/alecthomas/kong
    
    the code of the file until where you have to start completion: package kong

import (
	"fmt"
	"reflect"
	"strings"
)

type bindings map[reflect.Type]func() (reflect.Value, error)

func (b bindings) String() string {
	out := []string{}
	for k := range b {
		out = append(out, k.String())
	}
	return "bindings{" + strings.Join(out, ", ") + "}"
}

func (b bindings) add(values ...interface{}) bindings {
	for _, v := range values {
		v := v
		b[reflect.TypeOf(v)] = func() (reflect.Value, error) { return reflect.ValueOf(v), nil }
	}
	return b
}

func (b bindings) addTo(impl, iface interface{}) {
	val
    
func callAnyFunction(f reflect.Value, bindings bindings) (out []any, err error) {
	if f.Kind() != reflect.Func {
		return nil, fmt.Errorf("expected function, got %s", f.Type())
	}
	in := []reflect.Value{}
	t := f.Type()
	for i := 0; i < t.NumIn(); i++ {
		pt := t.In(i)
		if argf, ok := bindings[pt]; ok {
			argv, err := argf()
			if err != nil {
				return nil, err
			}
			in = append(in, argv)
		} else {
			return nil, fmt.Errorf("couldn't find binding of type %s for parameter %d of %s(), use kong.Bind(%s)", pt, i, t, pt)
		}
	}
	outv := f.Call(in)
	out = make([]any, len(outv))
	for i, v := range outv {
		out[i] = v.Interface()
	}
	return out, nil
}