code: public byte[] getBytes() {
      // avoid copy if `base` is `byte[]`
      if (offset == BYTE_ARRAY_OFFSET && base instanceof byte[]
        && ((byte[]) base).length == numBytes) {
        return (byte[]) base;
      } else {
        byte[] bytes = new byte[numBytes];
        copyMemory(base, offset, bytes, BYTE_ARRAY_OFFSET, numBytes);
        return bytes;
      }
    }
docs: Returns the underline bytes, will be a copy of it if it's part of another array.