code: function(face, absorbingFace) {
        var faceVertices = this.removeAllVerticesFromFace(face);
  
        if (faceVertices !== undefined) {
          if (absorbingFace === undefined) {
            // mark the vertices to be reassigned to some other face
  
            this.unassigned.appendChain(faceVertices);
          } else {
            // if there's an absorbing face try to assign as many vertices as possible to it
  
            var vertex = faceVertices;
  
            do {
              // we need to buffer the subsequent vertex at this point because the 'vertex.next' reference
              // will be changed by upcoming method calls
  
              var nextVertex = vertex.next;
  
              var distance = absorbingFace.distanceToPoint(vertex.point);
  
              // check if 'vertex' is able to see 'absorbingFace'
  
              if (distance > this.tolerance) {
                this.addVertexToFace(vertex, absorbingFace);
              } else {
                this.unassigned.append(vertex);
              }
  
              // now assign next vertex
  
              vertex = nextVertex;
            } while (vertex !== null);
          }
        }
  
        return this;
      }
docs: Removes all the visible vertices that 'face' is able to see