code: @Nonnull
    public CSSMediaQuery addMediaExpression (@Nonnull final CSSMediaExpression aMediaExpression)
    {
      ValueEnforcer.notNull (aMediaExpression, "MediaExpression");
  
      m_aMediaExpressions.add (aMediaExpression);
      return this;
    }
docs: Append a media expression to the list.
  
  @param aMediaExpression
  The media expression to be added. May not be <code>null</code>.
  @return this