tructure will be:
  &lt;Nb&gt;,&lt;br/&gt;
  [&lt;key-label-1&gt;,&lt;value-label-1&gt;],...,[&lt;key-label-Nb&gt;,&lt;value-label-Nb&gt;],&lt;br/&gt;
  [&lt;index-1&gt;,&lt;value-1&gt;],...,[&lt;index-Nv&gt;,&lt;value-Nv&gt;]

The serialized list will thus contain `Np + Nv + 1` elements:&lt;br/&gt;
  &lt;num-labels&gt;    - the total number of key-value label pairs&lt;br/&gt;
  &lt;key-label-j&gt;   - the key in the key-value label pair `j`&lt;br/&gt;
  &lt;value-label-j&gt; - the value in the key-value la