code: public void setOpacity(@FloatRange(from = 0.0f, to = 1.0f) float opacity) {
      this.opacity = opacity;
      if (!style.isFullyLoaded()) {
        // We are in progress of loading a new style
        return;
      }
  
      fillExtrusionLayer.setProperties(fillExtrusionOpacity(opacity));
    }
docs: Change the building opacity. Calls into changing the fill extrusion fill opacity.
  
  @param opacity {@code float} value between 0 (invisible) and 1 (solid)
  @since 0.1.0