title: Pie chart not showing data correctly
body: <p>My data model:</p>
  
  <pre><code>{
      "UserData": 
      {
          "firstName": "Pieter"
          "history": 
          [
              {
                  "clientID": 2,
                  "distance": "130"
              },
  
              {
                  "client": 3,
                  "distance": "300"
              }
  
              ,
  
              {
                  "client": 4,
                  "distance": "430"
              }
          ]
      }
  }
  </code></pre>
  
  <p><strong>View</strong>                        </p>
  
  <pre><code>                                        &lt;content&gt;
                          &lt;viz:ui5.Pie&gt;
                              &lt;viz:dataset&gt;
                                  &lt;viz:ui5.data.FlattenedDataset
                                      data="{/UserData/clockHistory}"&gt;
                                      &lt;viz:dimensions&gt;
                                          &lt;viz:ui5.data.DimensionDefinition
                                              axis="1" name="Client" value="{clientID}"&gt;
                                          &lt;/viz:ui5.data.DimensionDefinition&gt;
                                      &lt;/viz:dimensions&gt;
                                      &lt;viz:measures&gt;
                                          &lt;viz:ui5.data.MeasureDefinition
                                              name="Distance" value="{distance}"&gt;
                                          &lt;/viz:ui5.data.MeasureDefinition&gt;
                                      &lt;/viz:measures&gt;
                                  &lt;/viz:ui5.data.FlattenedDataset&gt;
                              &lt;/viz:dataset&gt;
                          &lt;/viz:ui5.Pie&gt;
                      &lt;/content&gt;
  </code></pre>
  
  <p>I am expecting three pieces in the pie size depending on the distance values.
  However I get a different result:</p>
  
  <p><img src="https://i.stack.imgur.com/ADFri.png" alt="enter image description here"></p>
  
  <p>If I have multiple items in the array of the same client id, will the pie chart automatically group the clients together and add their distances?</p>