@pimms.value<EOL><INDENT>def index(vertex_index, edge_index, face_index):<DEDENT>
idx = TesselationIndex(vertex_index, edge_index, face_index)<EOL>return idx.persist()<EOL>
tess.index is a TesselationIndex object that indexed the faces, edges, and vertices in the
given tesselation object. Vertex, edge, and face indices can be looked-up using the
following syntax:
  # Note that in all of these, u, v, and w are vertex *labels*, not vertex indices:
  tess.index[u]       # for vertex-label u => vertex-index of u
  tess.index[(u,v)]   # for edge (u,v) => edge-index of (u,v)
  tess.index[(u,v,w)] # for face (u,v,w) => face-index of (u,v,w)
Alternately, one may want to obtain the vertex indices of an object without obtaining the
indices for it directly:
  # Assume ui,vi,wi are the vertex indices of the vertex labels u,v,w:
  tess.index(u)       # for vertex-label u => ui
  tess.index((u,v))   # for edge (u,v) => (ui,vi)
  tess.index((u,v,w)) # for face (u,v,w) => (ui,vi,wi)
Finally, in addition to passing individual vertices or tuples, you may pass an appropriately
sized vector (for vertices) or matrix (for edges and faces), and the result will be a list
of the appropriate indices or an identically-sized array with the vertex indices.