private static CharBuffer grow(CharBuffer buf) {
    char[] copy = Arrays.copyOf(buf.array(), buf.capacity() * 2);
    CharBuffer bigger = CharBuffer.wrap(copy);
    Java8Compatibility.position(bigger, buf.position());
    Java8Compatibility.limit(bigger, buf.limit());
    return bigger;
  }

  /** Handle the case of underflow caused by needing more input characters. */
  private void readMoreChars() throws IOException {

    Java8Compatibility.flip(buf2);
    assertThat(buf2.toString()).isEqualTo(expected);
    assertFullyRead(reader);

    // read in chunks to fixed CharBuffer
    reader = new CharSequenceReader(charSequence);
    buf2 = CharBuffer.allocate(5);
    builder = new StringBuilder();
    while (reader.read(buf2) != -1) {
      Java8Compatibility.flip(buf2);
      builder.append(buf2);

  }

  /** Updates this hasher with bytes from the given buffer. */
  protected void update(ByteBuffer b) {
    if (b.hasArray()) {
      update(b.array(), b.arrayOffset() + b.position(), b.remaining());
      Java8Compatibility.position(b, b.limit());
    } else {
      for (int remaining = b.remaining(); remaining > 0; remaining--) {
        update(b.get());
      }
    }
  }

    Java8Compatibility.flip(buf2);
    assertThat(buf2.toString()).isEqualTo(expected);
    assertFullyRead(reader);

    // read in chunks to fixed CharBuffer
    reader = new CharSequenceReader(charSequence);
    buf2 = CharBuffer.allocate(5);
    builder = new StringBuilder();
    while (reader.read(buf2) != -1) {
      Java8Compatibility.flip(buf2);
      builder.append(buf2);

    }

    checkNotNull(from);
    checkNotNull(to);
    long total = 0;
    CharBuffer buf = createBuffer();
    while (from.read(buf) != -1) {
      Java8Compatibility.flip(buf);
      to.append(buf);
      total += buf.remaining();
      Java8Compatibility.clear(buf);
    }
    return total;
  }

  // TODO(lukes): consider allowing callers to pass in a buffer to use, some callers would be able

      StringBuilder builder = new StringBuilder();
      CharBuffer buffer = CharBuffer.allocate(100);
      while (reader.read(buffer) != -1) {
        Java8Compatibility.flip(buffer);
        builder.append(buffer);
        Java8Compatibility.clear(buffer);
      }
      return builder.toString();
    }
  }

  private static class UrlByteSourceFactory extends FileByteSourceFactory {

      ByteBuffer newBuffer = ByteBuffer.allocate(newCapacity).order(ByteOrder.LITTLE_ENDIAN);

      // We must switch the old buffer to read mode to extract data
      Java8Compatibility.flip(buffer);

      newBuffer.put(buffer);

      // Swap references, newBuffer is already in write mode at the correct position
      this.buffer = newBuffer;
    }

    @Override

        int limit = pos + random.nextInt(value.length - pos + 1);
        for (PrimitiveSink sink : sinks) {
          ByteBuffer buffer = ByteBuffer.wrap(value);
          Java8Compatibility.position(buffer, pos);
          Java8Compatibility.limit(buffer, limit);
          sink.putBytes(buffer);
          assertEquals(limit, buffer.limit());
          assertEquals(limit, buffer.position());
        }
      }
    },

    }

    ByteBuffer buf = ByteBuffer.wrap(createBuffer());
    long total = 0;
    while (from.read(buf) != -1) {
      Java8Compatibility.flip(buf);
      while (buf.hasRemaining()) {
        total += to.write(buf);
      }
      Java8Compatibility.clear(buf);
    }
    return total;
  }

  /** Max array length on JVM. */
  private static final int MAX_ARRAY_LEN = Integer.MAX_VALUE - 8;