Example.js javascript event handler appears broken

[victorromeo]

The provided example appears to be broken due to changes in the wrapper implementation by Google Charts. As a result, the click events are not handled, but instead report errors into the browser console log.

example.js:3 Uncaught TypeError: Cannot read property 'getChart' of undefined
    at my_function (example.js:3)
    at gvjs_F.<anonymous> (jsapi_compiled_default_module.js:151)
    at gvjs_ni (jsapi_compiled_default_module.js:150)
    at gvjs_F.gvjs_.dispatchEvent (jsapi_compiled_default_module.js:148)
    at gvjs_G (jsapi_compiled_default_module.js:150)
    at jsapi_compiled_default_module.js:466
    at gvjs_F.<anonymous> (jsapi_compiled_default_module.js:151)
    at gvjs_ni (jsapi_compiled_default_module.js:150)
    at gvjs_F.gvjs_.dispatchEvent (jsapi_compiled_default_module.js:148)
    at gvjs_G (jsapi_compiled_default_module.js:150)