code: function(evt) {
      const latlng = this._map.mouseEventToLatLng(evt.originalEvent), // get actual latlng instead of the marker's latlng from originalEvent
        lastClick = this._latlngs[this._latlngs.length - 1],
        vertexSymbol = this._symbols.getSymbol('measureVertex');
  
      if (!lastClick || !latlng.equals(lastClick)) {
        // skip if same point as last click, happens on `dblclick`
        this._latlngs.push(latlng);
        this._addMeasureArea(this._latlngs);
        this._addMeasureBoundary(this._latlngs);
  
        this._measureVertexes.eachLayer(function(layer) {
          layer.setStyle(vertexSymbol);
          // reset all vertexes to non-active class - only last vertex is active
          // `layer.setStyle({ className: 'layer-measurevertex'})` doesn't work. https://github.com/leaflet/leaflet/issues/2662
          // set attribute on path directly
          if (layer._path) {
            layer._path.setAttribute('class', vertexSymbol.className);
          }
        });
  
        this._addNewVertex(latlng);
  
        if (this._measureBoundary) {
          this._measureBoundary.bringToFront();
        }
        this._measureVertexes.bringToFront();
      }
  
      this._updateResults();
      this._updateMeasureStartedWithPoints();
    }
docs: handle map click during ongoing measurement add new clicked point, update measure layers and results ui