 class="comment">//-------------------------------------------------------------------------
</span>    <span class="comment">// (3) Finally we want to calculate the available manpower of the company
</span>    <span class="comment">// for the selected time scope: This is done by adding up the employees
</span>    <span class="comment">// working time maps:
</span>    <span class="identifier">interval_map</span><span class="special">&lt;</span><span class="identifier">date</span><span class="special">,</spa