我在REPL中测试一个简单的MultiMap
示例。
为什么我会遇到这个错误?
scala> val mm = new HashMap[Int, Set[String]] with MultiMap[Int, String]
mm: scala.collection.mutable.HashMap[Int,scala.collection.mutable.Set[String]] with scala.collection.mutable.MultiMap[Int,String] = Map()
scala> mm.addBinding(1, "a")
java.lang.AbstractMethodError: $anon$1.addBinding(Ljava/lang/Object;Ljava/lang/Object;)Lscala/collection/mutable/MultiMap;