map.clear
end
+ redef fun add_all(other) do
+ for k, v in other do
+ self[k] += v
+ end
+ end
+
# Count one more occurrence of `e`
fun inc(e: E)
do
# @toimplement by default just call `to_s` on the element
protected fun element_to_s(e: E): String
do
+ if e == null then return "null"
return e.to_s
end