How to test functions cdef'd in Cython? : <p>I have a .pyx file in which I define some functions, e.g.</p>

<pre><code>cdef double foo(double a) nogil:
    return 3. * a
</code></pre>

<p>How could I unit test the behavior of such functions outside the pyx file? Since they are cdef'd, I am not able to simply import them...</p>
