/**
 * Base class for all models (Player, Map, Round, etc.).
 * Adds serialization, cloning, and automatic comparison. */
export declare abstract class ModelBase {
    toJSON(): string;
    abstract toSerializableObject(): any;
    clone(): ModelBase;
    equals(other: ModelBase): boolean;
    fromJSON(json: string): ModelBase;
    protected validateString<T>(value: unknown): T | 'unknown';
    protected validateStringOrNull(value: unknown): string;
    protected validateNumberOrZero(value: unknown): number;
    protected validateNumberOrNull(value: unknown): number;
    protected validateNumber(value: unknown, defaultValue?: number): number;
}