code: @FactoryMethod
      public static NullExpectation create( String expected )
      {
          return "null".equalsIgnoreCase( expected ) || "nothing".equalsIgnoreCase( expected ) ?
                 new NullExpectation() :
                 null;
      }
docs: <p>create.</p>
  
  @param expected a {@link java.lang.String} object.
  @return a {@link com.greenpepper.expectation.NullExpectation} object.