title: Aggregate in MongodbCharts
body: <p>I'm having an error when I'm putting my aggregation in mongodbChart. This code is working fine in normal aggregation but when I'm putting it in MongodbCharts it gives me an error.</p>
  <p>FunctionError: (InvalidPipelineOperator) Invalid $addFields :: caused by :: Unrecognized expression '$group'</p>
  <p>code</p>
  <pre><code>{
      &quot;$group&quot;: {
        &quot;_id&quot;: &quot;$displayName&quot;,
        &quot;count&quot;: {
          &quot;$sum&quot;: 1
        }
      }
    },
    {
      &quot;$match&quot;: {
        &quot;_id&quot;: {
          &quot;$ne&quot;: null
        },
        &quot;count&quot;: {
          &quot;$gt&quot;: 1
        }
      }
    }
  </code></pre>