Apparently templating upper case Function is not supported:
When turning on compilation_mode="SIMPLE", they cause errors like:
[internal]:27809 ERROR - Too many template parameters
I checked the docs:
https://github.com/google/closure-compiler/wiki/Types-in-the-Closure-Type-System
Under "Instance Type":
"Also avoid using Function in favor of the more specific
function(...): ..."
Change-Id: I1cffbee0a7922be0fb7b40d3db6144aece46e0da
b57db23f7b