ng&nbsp;:&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;int&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;<span class="keywordsign">'</span>a<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;header_size&nbsp;:&nbsp;int<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;data_size&nbsp;:&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;int&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;int<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;total_size&nbsp;:&nbsp;stri