No function implementation vxUnpublishKernels

There is only an implementation of the function vxPublishKernels:
(https://github.com/KhronosGroup/openvx-samples/blob/master/bubble-pop/source/internal_publishKernels.cpp#:~:text=extern%20%22C%22%20%20SHARED_PUBLIC%20vx_status%20VX_API_CALL%20vxPublishKernels(vx_context%20context))

But the standard says
(https://registry.khronos.org/OpenVX/specs/1.3.1/html/OpenVX_Specification_1_3_1.html#:~:text=module)%3B-,The%20module%20must%20be%20a%20dynamic%20library%20with%20by%20convention%2C%20two%20exported%20functions%20named%20vxPublishKernels%20and%20vxUnpublishKernels%20%5BREQ-1923%5D.,-vxPublishKernels):
>The module must be a dynamic library with by convention, two exported functions named vxPublishKernels and
**vxUnpublishKernels** [REQ-1923].