Encoding INTEGER with set of allowed values

[maxime-esa]

Consider this type:

MyType ::= INTEGER (0 | 100)

If not wrong, using uPER I'd expect to use one bit for the encoding as there are 2 possible values.
EDIT actually this assumption is probably wrong, uPER would compute the number of bits based on a range (0..100) - but this leaves the open question:

However, I can't get any output:

>>> foo = asn1tools.compile_files('test.asn', 'uper')
>>> encoded = foo.encode('MyType', 100)
>>> encoded
b''    # Nothing?

Any idea?
Thanks!