docs: public static int copyAllBytes(InputStream in, OutputStream out) throws IOException {
          int byteCount = 0;
          byte[] buffer = new byte[BUFFER_SIZE];
          while (true) {
              int read = in.read(buffer);
              if (read == -1) {
                  break;
              }
              out.write(buffer, 0, read);
              byteCount += read;
          }
          return byteCount;
      }