description

# RegisterBinaryCallbackHandler typedef Null safety

ZoneBinaryCallback<R, T1, T2> RegisterBinaryCallbackHandler <R, T1, T2>(

1. Zone self,
2. ZoneDelegate parent,
3. Zone zone,
4. R f(
   1. T1 arg1,
   2. T2 arg2
   )

)

## Implementation

    typedef RegisterBinaryCallbackHandler
        = ZoneBinaryCallback<R, T1, T2> Function<R, T1, T2>(Zone self,
            ZoneDelegate parent, Zone zone, R Function(T1 arg1, T2 arg2) f);