Whats the meaning of the basic tests error message? With enough spamming I managed to pass the random tests without a precission error, but I have no idea what's the problem with this one.

basicTests(XbonacciTest)
9
randomTests(XbonacciTest)
Testing for signature: [15.0, 16.0, 17.0, 1.0, 7.0, 0.0, 13.0, 7.0, 8.0, 7.0, 14.0, 4.0, 7.0, 11.0, 17.0, 10.0] and n: 26
Testing for signature: [4.0, 10.0, 13.0, 6.0, 15.0, 8.0, 17.0, 19.0, 13.0, 6.0, 20.0, 14.0, 3.0, 1.0, 11.0, 12.0] and n: 64
expected:< 1.1583822108246636E16> but was:< 1.1583822108246634E16>
0 Passed
2 Failed
0 Errors

fibonacci is a xibonacci with a window size of 2, in that test you're asked about the 10 elment of a xibonacci(2) series (fibonacci series)