JPython and subclassing from an abstract class

[Pieter Laeremans]

Hi, 

I'm a newbie to python and tried to experiment a bit with JPython.
Can anyone explain why the following doesn't work?

Consider the following  java classes:

public class Rational {

public Rational(numerator, denominator){}

public long getDenominator(){}
public longgetNumerator(){}

}


public abstract class Constraint {

public abstract String getDescription();
public boolean satisifies(Rational rational);

}

I want to subclass this class in python but it doesn't work.
I've tried:

class testConstraint(Constraint):
	define getDescription(self):
		return "test"
	define satisfies(self, rational):
		return rational.getDenominator()

This didn't  work!
I could crate an instance
t = testConstraint
but when i tried
r = Rational(2,1)
t.satisfies(r)

I got an error message.

Thx in advance!

Pieter