Before revision:  We propose two alternatives that are not (or much less) affected by heterogenous data distributions: a new method that is only applicable to strongly convex problems, and  we point out a more general approach that is applicable to linear compressors  .
After revision:  We propose two alternatives that are not (or much less) affected by heterogenous data distributions: a new method that is only applicable to strongly convex problems, and secondly, we point out a more general approach that is applicable to linear compressors .