How to use the sunpy.Spatial.loadData function in sunpy

def loadData(self):
        """
        Overloaded loadData function - updates the unstructured grid object
        """
        Spatial.loadData(self)
        if self.is3D:
            self.data=np.ravel(self.data[self.mask3D])
        else:
            self.data=np.ravel(self.data)
            
        self.ug.cell_data.scalars = self.data
        self.ug.cell_data.scalars.name = 'suntans_scalar' 
        self.ug.modified()