def to_tess(obj):
if   is_tess(obj): return obj<EOL>elif is_mesh(obj): return obj.tess<EOL>elif is_topo(obj): return obj.tess<EOL>else:<EOL><INDENT>try:    return tess(obj)<EOL>except Exception: pass<EOL>try:    return to_mesh(obj).tess<EOL>except Exception: pass<EOL><DEDENT>raise ValueError('<STR_LIT>')<EOL>
to_tess(obj) yields a Tesselation object that is equivalent to obj; if obj is a tesselation
  object already and no changes are requested (see options) then obj is returned unmolested.

The following objects can be converted into tesselations:
  * a tesselation object
  * a mesh or topology object (yields their tess objects)
  * a 3 x n or n x 3 matrix of integers (the faces)
  * a tuple of coordinates and faces that can be passed to to_mesh