docs: protected ByteBuffer __vector_in_bytebuffer(ByteBuffer bb, int vector_offset, int elem_size) {
      int o = this.__offset(vector_offset);
      if (o == 0) return null;
      int vectorstart = __vector(o);
      bb.rewind();
      bb.limit(vectorstart + __vector_len(o) * elem_size);
      bb.position(vectorstart);
      return bb;
    }