updated aggregate handler

Civi/DataProcessor/FieldOutputHandler/NumberFieldOutputHandler.php

@@ -81,6 +81,31 @@ class NumberFieldOutputHandler extends AbstractSimpleFieldOutputHandler implemen
     }
   }
 
+  /**
+   * Enable aggregation for this field.
+   *
+   * @return void
+   */
+  public function enableAggregation() {
+    $dataFlow = $this->dataSource->ensureField($this->getAggregateFieldSpec());
+    if ($dataFlow) {
+      $dataFlow->addAggregateOutputHandler($this);
+    }
+  }
+
+  /**
+   * Disable aggregation for this field.
+   *
+   * @return void
+   */
+  public function disableAggregation() {
+    $dataFlow = $this->dataSource->ensureField($this->getAggregateFieldSpec());
+    if ($dataFlow) {
+      $dataFlow->removeAggregateOutputHandler($this);
+    }
+  }
+
+
   /**
    * When this handler has additional configuration you can add
    * the fields on the form with this function.