public void Allow <TType, TPropertyType>(TType instance, Expression <Func <TType, TPropertyType> > propertySelector, Func <TPropertyType, TPropertyType, bool> propertyComparison) { MemberExpression memberExpression = GetMemberExpression(propertySelector); _objectComparer.Allow(instance, new PropertyComparator { Property = memberExpression.Member, Comparator = propertyComparison }); }