Mesh volume

        Returns
        -------
        volume : float
            Total volume of the mesh.

def volume(self):
        """
        Mesh volume

        Returns
        -------
        volume : float
            Total volume of the mesh.

        """
        sizes = self.compute_cell_sizes(length=False, area=False, volume=True)
        return np.sum(sizes.cell_arrays['Volume'])