Hi
I found org.apache.spark.ml.feature.Word2Vec.transform() very slow. I think we should not read broadcast every sentence, so I fixed on my forked. https://github.com/979969786/spark/commit/a9f894df3671bb8df2f342de1820dab3185598f3 I have use 20000 number rows test it. Original version consume *5 minutes*, and my version just consume *22 seconds* on same data. If I'm right, I will pull request. Thanks
