var testString string // test data for write tests
var testBytes []byte  // test data; same as testString but as a slice.

type negativeReader struct{}

func (r *negativeReader) Read([]byte) (int, error) { return -1, nil }

func init() {
	testBytes = make([]byte, N)
	for i := 0; i < N; i++ {
		testBytes[i] = 'a' + byte(i%26)
	}
	testString = string(testBytes)
}

// Verify that contents of buf match the string s.

  @GwtIncompatible // java.nio.charset.Charset
  public void testIsWellFormed_1Byte() {
    testBytes(1, EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
  }

  /** Tests that round tripping of all two byte permutations work. */
  @GwtIncompatible // java.nio.charset.Charset
  public void testIsWellFormed_2Bytes() {
    testBytes(2, EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
  }