@@ -0,0 +1,573 @@
+import sys%0Afrom copy import deepcopy%0Aimport pytest%0Aimport numpy as np%0Afrom numpy.random import random, randint%0A%0Afrom flare import env, struc, gp%0Afrom flare.kernels.utils import str_to_kernel_set as stks%0A%0A@pytest.mark.parametrize('kernel_name', %5B'2mc', '3mc', '2+3mc', '2', '3',%0A                                         '2+3'%5D)%0Adef test_stk(kernel_name):%0A    %22%22%22Check whether the str_to_kernel_set can return kernel functions%0A    properly%22%22%22%0A%0A    try:%0A        k, kg, ek, efk = stks(kernel_name)%0A    except:%0A        raise RuntimeError(f%22fail to return kernel %7Bkernel_name%7D%22)%0A

add unit test for stk