code: @Override
      public R visitIntersection(IntersectionType t, P p) {
          return visitUnknown(t, p);
      }
docs: {@inheritDoc}
  
  @implSpec Visits an {@code IntersectionType} element by calling {@code
  visitUnknown}.
  
  @param t  {@inheritDoc}
  @param p  {@inheritDoc}
  @return the result of {@code visitUnknown}
  
  @since 1.8