code: @Override
      public boolean matches(Object obj) {
          if (!(obj instanceof Throwable))
              return false;
  
          Throwable throwable = (Throwable) obj;
  
          return throwable.getCause() == null;
      }
docs: /*
  (non-Javadoc)
  
  @see org.hamcrest.Matcher#matches(java.lang.Object)