fixed booktests

docs/Map.md

@@ -94,7 +94,8 @@ Or iterate its key-value pairs that are instances of [MapEntry] class:
 
     val map = Map( ["foo", 1], ["bar", "buzz"], [42, "answer"] )
     for( entry in map ) {
-        println("map[%s] = %s"(entry.key, entry.value))
+        val e: MapEntry = entry as MapEntry
+        println("map[%s] = %s"(e.key, e.value))
     }
     void
     >>> map[foo] = 1
@@ -175,4 +176,4 @@ Notes:
 - Spreads inside map literals and `+`/`+=` merges allow any objects as keys.
 - When you need computed or non-string keys, use the constructor form `Map(...)`, map literals with computed keys (if supported), or build entries with `=>` and then merge.
 
-[Collection](Collection.md)
+[Collection](Collection.md)