TAG func4(int n) {
    void *fptr;
    TAG retval;

    fptr = dlsym(_Chsample_handle, "func4_chdl");
    if(fptr == NULL) {
        fprintf(_stderr, "Error: %s(): dlsym(): %s\n", __func__,  dlerror());
        return retval;
    }
    dlrunfun(fptr, NULL, NULL, &retval, n);
    return retval;
}
