@Nullable
    @Contract(value = "null -> null; !null -> !null", pure = true)
    public static <T> Supplier<T> wrapSupplier(@Nullable Supplier<T> supplier) {
        if (supplier == null) return null;
        else if (supplier instanceof TtlEnhanced) return supplier;
        else return new TtlSupplier<>(supplier);
    }
wrap {@link Supplier} to TTL wrapper.

@param supplier input {@link Supplier}
@return Wrapped {@link Supplier}
@see TtlWrappers#unwrap(Object)
ttl-core/src/main/java/com/alibaba/ttl3/TtlWrappers.java