FW/1's "buildURL" query string param is type "any" (to allow a struct or a string), as should be the case with the plugin.

https://github.com/seancorfield/fw1/wiki/Reference-Manual#public-string-function-buildurl-string-action---string-path--see-below-any-querystring---
Merge pull request #19 from jamiejackson/develop

FW/1's "buildURL" query string param is type "any" (to allow a struct or...