src/java.base/share/classes/java/io/FilterInputStream.java

@@ -57,13 +57,10 @@
      *
      * @param   in   the underlying input stream, or <code>null</code> if
      *          this instance is to be created without an underlying stream.
      */
     protected FilterInputStream(InputStream in) {
-        if (in == null) {
-            throw new NullPointerException();
-        }
         this.in = in;
     }
 
     /**
      * Reads the next byte of data from this input stream. The value