option to pass TextStyle parameter in the toTextSpan method

Hi there,
Can you help me change the definition of toTextSpan method. I want to change the theme based on the dark and light theme which would be only posssible with the below code:

static TextSpan toTextSpan(BuildContext context, String htmlContent,TextStyle textStyle,
{Function linksCallback}) {
Parser p = Parser(context, htmlContent, linksCallback: linksCallback);
return TextSpan(style:textStyle, text: "", children: p.parse());
}