for ; n > 0; n-- {
		m, err := buf.WriteString(fus)
		if m != len(fus) {
			t.Errorf(testname+" (fill 2): m == %d, expected %d", m, len(fus))
		}
		if err != nil {
			t.Errorf(testname+" (fill 3): err should always be nil, found err == %s", err)
		}
		s += fus
		check(t, testname+" (fill 4)", buf, s)
	}
	return s
}

// Fill buf through n writes of byte slice fub.

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

import (
	"fmt"
	"os"
)

func main() {
	if len(os.Args) != 2 {
		fatal("usage: callback testname")
	}
	switch os.Args[1] {
	default:
		fatal("unknown test %q", os.Args[1])
	case "Call":
		testCall()
	case "Callback":
		testCallback()
	}
	println("OK")
}