//			log.Fatal(err)
//		}
//
//		biggerZip := makeZip("big.zip", bytes.NewReader(bigZip))
//		if err := os.WriteFile("/tmp/bigger.zip", biggerZip, 0666); err != nil {
//			log.Fatal(err)
//		}
//
//		biggestZip := makeZip("bigger.zip", bytes.NewReader(biggerZip))
//		if err := os.WriteFile("/tmp/biggest.zip", biggestZip, 0666); err != nil {
//			log.Fatal(err)
//		}
//	}
//

package bytes_test

import (
	. "bytes"
	"fmt"
	"internal/testenv"
	"io"
	"math/rand"
	"strconv"
	"testing"
	"unicode/utf8"
)

const N = 10000       // make this bigger for a larger (and slower) test
var testString string // test data for write tests
var testBytes []byte  // test data; same as testString but as a slice.

type negativeReader struct{}

In an expression switch,
the switch expression is evaluated and
the case expressions, which need not be constants,
are evaluated left-to-right and top-to-bottom; the first one that equals the
switch expression
triggers execution of the statements of the associated case;
the other cases are skipped.
If no case matches and there is a "default" case,
its statements are executed.

In an expression switch,
the switch expression is evaluated and
the case expressions, which need not be constants,
are evaluated left-to-right and top-to-bottom; the first one that equals the
switch expression
triggers execution of the statements of the associated case;
the other cases are skipped.
If no case matches and there is a "default" case,
its statements are executed.

		return ((r - 'A' + step) % 26) + 'A'
	}
	return r
}

func TestMap(t *testing.T) {
	// Run a couple of awful growth/shrinkage tests
	a := tenRunes('a')

	// 1.  Grow. This triggers two reallocations in Map.
	maxRune := func(r rune) rune { return unicode.MaxRune }
	m := Map(maxRune, []byte(a))
	expect := tenRunes(unicode.MaxRune)
	if string(m) != expect {