def METHOD_NAME(self, mesh, p=None):
    if p is None:
        p = self.vemspace.p
    self.vemspace = VirtualElementSpace2d(mesh, p) 
    self.mesh = self.vemspace.mesh
    self.uh = self.vemspace.function() 
    self.area = self.vemspace.smspace.area
    self.integralalg = PolygonMeshIntegralAlg(
            self.integrator, 
            self.mesh, 
            area=self.area, 
            barycenter=self.vemspace.smspace.barycenter)
    #self.uI = self.vemspace.interpolation(self.pde.solution, self.integralalg.integral)
    self.mat = doperator.basic_matrix(self.vemspace, self.area)