I am also stuck there

It can be done simply by lowering delta:

assertEquals(5881.25D, Circle.area(43.2673), 0.001);

or by comparing strings:

assertEquals("5881.25", String.valueOf(Circle.area(43.2673)));

I didn't round the numbers and it accepted my solution, please fix it :)

Made it clear that we have 4 specific instructions on this Kata.

Edited description

Hello!
When I try to submit my solution ( that passes simple test ) I have this error:

fullTest(EncodeTest)
Failed special encoding
Any help??

This is just an incredibly bad kata. It has minor edge cases that trip you up that aren't hand-held in the default tests (the null case).

It takes far too long, because you have to go through the mind-numbing process of copy-pasting every single leetspeak character into some sort of processable data structure. Protip: testing my ability to copy everything into vim to automate repetitive text replacement tasks doesn't help me learn java.

It forces you to use an abstract inheritance in a case that I think is just horribly overengineered (but this is java so I mean, that's an argument, not a complaint). But even then, the abstract class is completely given for you, which makes the thing seem so superfluous.

As far as I'm concerned, Kata are supposed to give me bite-size challenges that help me learn language features, not give me some cool end product. I think, in pursuing that end, this Kata just totally missed the point. I would have marked this as 'major issues' if I had the reputation to do so.

I didn't add support to no arrays and my answer was validated, take a look.

What do you suggest!!

The explanation is very bad formatted, and the problem is very vague.

Add a BIG NOTE about the special characters... please....

Will do better on the next Kata. This was very basic, and so did not put much effort.
Thanks,

Fixed this. Thanks!

the tests seem to require multiple spaces between sentencies, but the description of the kata does not specifies those spaces.

Double spaces in the test, instead of single spaces as the Instructions say.