neno">   47</span>&#160;  <span class="keywordtype">void</span> ping();</div><div class="line"><a name="l00048"></a><span class="lineno">   48</span>&#160;</div><div class="line"><a name="l00049"></a><span class="lineno">   49</span>&#160; <span class="keyword">protected</span>:</div><div class="line"><a name="l00050"></a><span class="lineno">   50</span>&#160; <span class="keyword">private</span>:</div><div class="line"><a name="l00051"></a><span class="lineno">   51</span>&#160;  <a class="code" href="cla