src/java.base/share/classes/java/lang/reflect/Layer.java

@@ -244,11 +244,10 @@
          *
          * @see Module#addOpens
          */
         public Controller addOpens(Module source, String pn, Module target) {
             Objects.requireNonNull(source);
-            Objects.requireNonNull(source);
             Objects.requireNonNull(target);
             ensureInLayer(source);
             Modules.addOpens(source, pn, target);
             return this;
         }

@@ -539,11 +538,11 @@
      * given function. The class loader delegation implemented by these class
      * loaders must respect module readability. The class loaders should be
      * {@link ClassLoader#registerAsParallelCapable parallel-capable} so as to
      * avoid deadlocks during class loading. In addition, the entity creating
      * a new layer with this method should arrange that the class loaders are
-     * ready to load from these module before there are any attempts to load
+     * ready to load from these modules before there are any attempts to load
      * classes or resources.
      *
      * <p> Creating a {@code Layer} can fail for the following reasons: </p>
      *
      * <ul>