pub unsafe extern "C" fn libssh2_session_init_ex(
    alloc: Option<LIBSSH2_ALLOC_FUNC>,
    free: Option<LIBSSH2_FREE_FUNC>,
    realloc: Option<LIBSSH2_REALLOC_FUNC>,
    abstrakt: *mut c_void
) -> *mut LIBSSH2_SESSION