title: Prometheus grouping by label
body: <p>I have a Gauge with labels no and type.Let's say my some metrics are:</p>
  
  <pre><code>dbValues{no="10",type="invoice"} 1
  dbValues{no="054017843",type="archive"} 1
  dbValues{no="0562447",type="receipt"} 1 
  dbValues{no="10",type="archive"} 1
  </code></pre>
  
  <p>I want to group these metrics by their no.Is there a possible way to do this?</p>