code: @Nonnull
    public CSSRect setTop (@Nonnull @Nonempty final String sTop)
    {
      ValueEnforcer.notEmpty (sTop, "Top");
  
      m_sTop = sTop;
      return this;
    }
docs: Set the top coordinate.
  
  @param sTop
  May neither be <code>null</code> nor empty.
  @return this