 fixed formatter</span>
f4 = hx.format.fixed(<span class="hljs-number">3</span>)
f4(<span class="hljs-number">9.9999</span>)        <span class="hljs-comment">// 10.000</span>
f4(<span class="hljs-number">1.1111</span>)        <span class="hljs-comment">// 1.111</span>
f4(<span class="hljs-number">1.5555</span>)        <span class="hljs-comment">// 1.556</span>
f4(<span class="hljs-number">10.5555</span>)       <span class="hljs-comment">// 10.556</span>
f4(<span class="hljs-number">100.5555</span>)      <s