Add some comments

main/core/src/util/Loggers.scala

@@ -189,7 +189,10 @@ case class MultiLogger(colored: Boolean, logger1: Logger, logger2: Logger) exten
   }
 }
 
-
+/**
+  * A Logger that forwards all logging to another Logger.  Intended to be
+  * used as a base class for wrappers that modify logging behavior.
+  */
 case class ProxyLogger(logger: Logger) extends Logger {
   def colored = logger.colored
 

main/src/modules/Jvm.scala

@@ -491,6 +491,13 @@ object Jvm {
     (deps.toSeq, resolution)
   }
 
+  /**
+    * A Coursier Cache.Logger implementation that updates the ticker with the count and
+    * overall byte size of artifacts being downloaded.
+    *
+    * In practice, this ticket output gets prefixed with the current target for which
+    * dependencies are being resolved, using a ProxyLogger subclass.
+    */
   class TickerResolutionLogger(ctx: mill.util.Ctx.Log) extends Cache.Logger {
     case class DownloadState(var current: Long, var total: Long)
     var downloads = new mutable.TreeMap[String,DownloadState]()