code: private void setZoomInMap() {
          if (getInitialized()) {
              final int zoomInt = (int) getZoom();
              if (logger.isTraceEnabled()) {
                  logger.trace("setting zoom in OpenLayers map: {}, animation: {}", zoomInt, animationDuration.get());
              }
              jsMapView.call("setZoom", zoomInt, animationDuration.get());
          }
      }
docs: sets the value of the actual zoom property in the OL map.