stream[@@can.getKeyValue](key)

can-reflect.getKeyValue will use this function to read the last emitted value or error by this stream.

Note, streams only have a value if onKeyValue is used to listen to changes. Use Kefir properties if you want to always be able to read a value.

The following creates a stream that immediately emits a value. When onKeyValue is used to listen to changes, it will immediately log 1. However, that value is preserved so getKeyValue can still be used:

var Kefir = require("can-kefir");

var stream = Kefir.stream(function(emit){
    emit.value(1);
});

canReflect.onKeyValue(stream, "value", function(newVal){
    console.log("new value", newVal);
}); // logs 1

canReflect.getKeyValue(stream,"value") //-> 1