def make_mesh(self, coords, properties=None, meta_data=None):
md = self.meta_data<EOL>if meta_data is not None: md = pimms.merge(md, meta_data)<EOL>return Mesh(self, coords, meta_data=md, properties=properties)<EOL>
tess.make_mesh(coords) yields a Mesh object with the given coordinates and with the
  meta_data and properties inhereted from the given tesselation tess.