export declare class HelpContentsRegistry {
    private static helpFields;
    private static overrides;
    /**
     * Returns the configured help value, or null if nothing is configured
     * @param key the key
     * @returns the configured help value, or null
     */
    static getHelpField(key: string): string;
    /**
     * Adds a help field to the registry. This value can be overridden by calling #registerOverride
     * If an override has been configured, this call will *not* change the already-configured value
     * @param key the key
     * @param val the value
     */
    static register(key: string, val: string): void;
    /**
     * Adds a help field to the registry and locks it, preventing subsequent registrations with the same key from
     * replacing its value. Subsequent calls to this method with the same key will have no effect on the value.
     *
     * @param key the key
     * @param val the value
     */
    static registerOverride(key: string, val: string): void;
}