private static JsonNode createVisibilityOnStylerForFeatureType(@Nullable final String featureType, final boolean on) {
        final ObjectNode node = JsonUtils.createObjectNode();
        if (featureType != null) {
            JsonUtils.setText(node, "featureType", featureType);
        }
        final ObjectNode visibilityNode = JsonUtils.createObjectNode();
        JsonUtils.setText(visibilityNode, "visibility", on ? "on" : "off");
        final ArrayNode stylers = JsonUtils.createArrayNode();
        stylers.add(visibilityNode);
        JsonUtils.set(node, "stylers", stylers);
        return node;
    }
Creates JSON like following example:
{
    "featureType": "parameter",
    "stylers": [
      {
        "visibility": "on"
      }
    ]
  }
main/src/main/java/cgeo/geocaching/unifiedmap/googlemaps/GoogleMapsThemeHelper.java