}

    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 {

        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;