/** Later keys override earlier (last wins). */
export declare function mergeParams(...layers: readonly (Record<string, unknown> | undefined)[]): Record<string, unknown>;
/** Python `ChainMap`: first layer wins per key (user > elm > defaults > dwg > global). */
export declare function mergeParamsFirstWins(...layers: readonly (Record<string, unknown> | undefined)[]): Record<string, unknown>;
export declare function getParam<T>(params: Record<string, unknown>, key: string, fallback: T): T;