Function lightgbm_sys::LGBM_BoosterSaveModel

pub unsafe extern "C" fn LGBM_BoosterSaveModel(
    handle: BoosterHandle, 
    start_iteration: c_int, 
    num_iteration: c_int, 
    feature_importance_type: c_int, 
    filename: *const c_char
) -> c_int

\brief Save model into file. \param handle Handle of booster \param start_iteration Start index of the iteration that should be saved \param num_iteration Index of the iteration that should be saved, <= 0 means save all \param feature_importance_type Type of feature importance, can be C_API_FEATURE_IMPORTANCE_SPLIT or C_API_FEATURE_IMPORTANCE_GAIN \param filename The name of the file \return 0 when succeed, -1 when failure happens