Map type is sometimes shown with only one generic argument type

[floitschG]

for the invocation-class [0] the Map type for the named arguments states that it only has one generic argument. I'm guessing the second one is dynamic, but it's not clear.

[0] https://api.dartlang.org/1.12.1/dart-core/Invocation-class.html

[sethladd]

Good catch, thanks!

here's a direct link to the named arguments: https://api.dartlang.org/1.12.1/dart-core/Invocation/namedArguments.html

[sethladd]

Duped by #919