The file names are congruent with the names given at scala 2.10.x branch with only difference being the prefix Spark. It is always possible to see diff, so, felt writing NOTE, unless there is a specific reason for doing something that other maintainer shall be careful about, is redundant. There are comments in the code mentioned otherwise. Please take a closer look and let me know if you find something specific that can be improved. 

About above file, you are right. Only reason, I had to copy paste it is to solve a type mismatch.