JavaScript import() and export() function usage

I once read about the import() and export() functions and how they relate to frames and that sort of deprecated practices. But i'm wondering if there's any practical use case for these functions on the client side.

Has anybody put import() and export() to use in an interesti开发者_StackOverflow社区ng way on the browser?

Is there a practical usage with say iFrames?

I was looking at the spec and the MDC docs, but there's really very little regarding these function.

https://developer.mozilla.org/en/JavaScript/Reference/Statements/import

https://developer.mozilla.org/en/JavaScript/Reference/Statements/export

These functions were deprecated back in Netscape 4. They actually only ever worked in Netscape 4.