'Check if CustomKernel works when the input array/list
sums to zero.'

def test_custom_1D_kernel_zerosum(self):

    array = [(-2), (-1), 0, 1, 2]
    custom = CustomKernel(array)
    custom.normalize()
    assert (custom.truncation == 0.0)
    assert (custom._kernel_sum == 0.0)
