byte[] buf = new byte[4];
    int numOfByteRead = in.read(buf, 0, buf.length);
    assertEquals(4, numOfByteRead);
    for (int i = 0; i < testBytes.length; i++) {
      assertEquals(testBytes[i], buf[i]);
    }

    verify(hasher).putBytes(testBytes, 0, testBytes.length);
    verify(hashFunction).newHasher();
    verifyNoMoreInteractions(hashFunction, hasher);
  }

    byte[] buf = new byte[4];
    int numOfByteRead = in.read(buf, 0, buf.length);
    assertEquals(4, numOfByteRead);
    for (int i = 0; i < testBytes.length; i++) {
      assertEquals(testBytes[i], buf[i]);
    }

    verify(hasher).putBytes(testBytes, 0, testBytes.length);
    verify(hashFunction).newHasher();
    verifyNoMoreInteractions(hashFunction, hasher);
  }

  @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);
  }