Function libxslt::bindings::xmlRelaxNGSetValidErrors

pub unsafe extern "C" fn xmlRelaxNGSetValidErrors(
    ctxt: *mut _xmlRelaxNGValidCtxt, 
    err: Option<unsafe extern "C" fn(*mut c_void, *const i8, ...)>, 
    warn: Option<unsafe extern "C" fn(*mut c_void, *const i8, ...)>, 
    ctx: *mut c_void
)