 a series involve implicitly constructing an <a href="index/Slice.html" class="extype" name="org.saddle.index.Slice">org.saddle.index.Slice</a>
object and passing it to the Series apply method:</p><pre>s(<span class="lit">'a'</span>-&gt;<span class="lit">'b'</span>) == Series(<span class="lit">'a'</span>-&gt;<span class="num">1</span>, <span class="lit">'b'</span>-&gt;<span class="num">2</span>, <span class="lit">'b'</span>-&gt;<span class="num">3</span>)
s(* -&gt; <span class="lit">'b'</span>) == Series(<s