[web2py] SQLCustomType no longer importable

[Fran]

Traceback (most recent call last):
  File "C:\Bin\web2py\gluon\restricted.py", line 188, in restricted
    exec ccode in environment
  File "C:/Bin/web2py/applications/eden/models/00_db.py", line 21, in
<module>
    from gluon.sql import SQLCustomType
ImportError: cannot import name SQLCustomType

Are we not supposed to use these any more?
If not, what should they be replaced by?

F