/**
 * Any `mask-type` CSS declaration. Even `luminance` matters, because it has
 * to win over a presentation attribute that says otherwise. As a substring
 * test it can false-positive (the string may occur in text content), which
 * only costs a parse that then changes nothing.
 */
export declare const HAS_MASK_TYPE_DECLARATION: RegExp;
/**
 * The value of the last `mask-type` declaration in a `style` attribute. The
 * last one wins, as it does in CSS. The value comes back lowercased: CSS
 * keywords are case-insensitive while SVG attribute values are not, and
 * resvg would reject a verbatim `Alpha` and silently fall back to the
 * default.
 */
export declare function declaredMaskType(style: unknown): string | undefined;