Added @skipif to test_prev_prime

test/test_mpz.py

@@ -5,11 +5,11 @@
 
 from hypothesis import assume, given, example, settings
 from hypothesis.strategies import booleans, integers, sampled_from
-from pytest import raises
+from pytest import raises, mark
 
 from gmpy2 import (mpz, pack, unpack, cmp, cmp_abs, to_binary, from_binary,
                    random_state, mpz_random, mpz_urandomb, mpz_rrandomb,
-                   prev_prime)
+                   prev_prime, mp_version)
 from supportclasses import a, b, c, d, z, q
 
 
@@ -311,7 +311,7 @@ def test_mpz_rrandomb():
     assert (mpz_rrandomb(random_state(42), 64).digits(2) ==
             '1111111111111111111111111100000000111111111111111111000000000000')
 
-
+@mark.skipif(mp_version() < "GMP 6.3.0", reason="requires GMP 6.3.0 or higher")
 def test_prev_prime():
     assert prev_prime(3) == mpz(2)
     assert prev_prime(4) == mpz(3)