[squash] remove Objects.requireNonNull

Author: NthPortal

src/library/scala/collection/Iterator.scala

@@ -1,7 +1,6 @@
 package scala.collection
 
 import java.io.{ObjectInputStream, ObjectOutputStream}
-import java.util.Objects
 
 import scala.collection.mutable.{ArrayBuffer, Builder, ImmutableBuilder}
 import scala.annotation.tailrec
@@ -1097,7 +1096,11 @@ object Iterator extends IterableFactory[Iterator] {
 
     override def hasNext: Boolean = {
       if (nextResult eq null) {
-        nextResult = Objects.requireNonNull(f(state), "null during unfold")
+        nextResult = {
+          val res = f(state)
+          if (res eq null) throw new NullPointerException("null during unfold")
+          res
+        }
         state = null.asInstanceOf[S] // allow GC
       }
       nextResult.isDefined