export declare function normalizeNullableString(value: unknown): string | null;
export declare function normalizeOptionalString(value: unknown): string | undefined;
export declare function normalizeOptionalLowercaseString(value: unknown): string | undefined;
export declare function normalizeLowercaseStringOrEmpty(value: unknown): string;
export declare function normalizeStringEntries(values: ReadonlyArray<unknown>): string[];
export declare function uniqueStrings(values: Iterable<string>): string[];