drop cb

Author: yuehhua

README.md

@@ -57,8 +57,7 @@ And then train as a Flux model.
 ```
 loss(𝐱, 𝐲) = sum(abs2, 𝐲 .- fno(𝐱)) / size(𝐱)[end]
 opt = Flux.Optimiser(WeightDecay(1f-4), Flux.ADAM(1f-3))
-call_back = Flux.throttle(validate, 5, leading=false, trailing=true)
-Flux.@epochs 50 Flux.train!(loss, params(m), data, opt, cb=call_back)
+Flux.@epochs 50 Flux.train!(loss, params(m), data, opt)
 ```
 
 ## Examples