es: no-common-ligatures; color: #848784">// use equivalence, i.e. !(a&lt;b) &amp;&amp; !(b&lt;a), rather than equality, i.e.</span><span style="font: 11.0px Menlo; font-variant-ligatures: no-common-ligatures"><br/></span><span style="font: 11.0px Menlo; font-variant-ligatures: no-common-ligatures; color: #848784">// a == b, which makes more sense for maps if you passed them a different</span><span style="font: 11.0px Menlo; font-variant-ligatures: no-common-ligatures"><br/></span><span style="font: 11.0px M