To develop rule:
sbt ~tests/test
# edit rules/src/main/scala/fix/SparkAutoUpgrade.scala
https://github.com/scala/scala-rewrites -
fix.scala213.Any2StringAdd fix.scala213.Core fix.scala213.ExplicitNonNullaryApply fix.scala213.ExplicitNullaryEtaExpansion fix.scala213.NullaryHashHash fix.scala213.ScalaSeq fix.scala213.Varargs