add one more api doc

mbernasocchi · nyalldawson · commit a08c8b77a5eb · 2019-01-21T17:46:58.000+11:00
(cherry picked from commit 305131c)
diff --git a/src/core/symbology/qgssymbollayer.h b/src/core/symbology/qgssymbollayer.h
@@ -317,6 +317,7 @@ class CORE_EXPORT QgsSymbolLayer
      * Sets a data defined property for the layer. Any existing property with the same key
      * will be overwritten.
      * \see dataDefinedProperties()
+     * \see Property
      * \since QGIS 3.0
      */
     virtual void setDataDefinedProperty( Property key, const QgsProperty &property );
@@ -375,6 +376,7 @@ class CORE_EXPORT QgsSymbolLayer
     /**
      * Returns a reference to the symbol layer's property collection, used for data defined overrides.
      * \see setDataDefinedProperties()
+     * \see Property
      * \since QGIS 3.0
      */
     QgsPropertyCollection &dataDefinedProperties() { return mDataDefinedProperties; }
