title: How to concatenate a flowVar to Json payload in Mule Dataweave
body: <p>incoming payload:</p>
  
  <pre><code>{
      "Categories": [
          {
              "ID": "5a873ca3",
              "Code": "CTY"
          }, {
              "ID": "89k873c8",
              "Code": "CTY"
          }
      ]
  }
  </code></pre>
  
  <p>flowVar value is an ArrayList: ([84hkj569],[6j93hl9])</p>
  
  <p>desired output payload:</p>
  
  <pre><code>  {
          "Categories": [
              {
                  "ID": "5a873ca3",
                  "Code": "CTY"
              }, {
                  "ID": "89k873c8",
                  "Code": "CTY"
              }, {
                  "ID": "84hkj569",
                  "Code": "CTY"
              }, {
                  "ID": "6j93hl9",
                  "Code": "CTY"
              }
          ]
      }
  </code></pre>
  
  <p>I couldn't find a way to do in dataweave, 
  Would you please help</p>