export declare function readStringValue(value: unknown): string | undefined;
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 lowercasePreservingWhitespace(value: string): string;
export declare function hasNonEmptyString(value: unknown): value is string;