[error] Note: (com.twitter.summingbird.batch.Timestamp, T) <: Any, but class BaseBolt is invariant in type I.
[error] You may wish to define I as +I instead. (SLS 4.5)
[error] Note: ((K, com.twitter.summingbird.batch.BatchID), (com.twitter.summingbird.batch.Timestamp, V)) <: Any, but class BaseBolt is invariant in type O.
[error] You may wish to define O as +O instead. (SLS 4.5)
[error]       case Some(s) => getFFMBolt[Any, Any, Any](s)//.asInstanceOf[BaseBolt[Any, Any]]


Changing the variance comes up with places I in base bolt is both covariant and contravariant in use