The DocumentStyle interface provides a mechanism by which the
style sheets embedded in a document can be retrieved. The expectation is
that an instance of the DocumentStyle interface can be
obtained by using binding-specific casting methods on an instance of the
Document interface.
A list containing all the style sheets explicitly linked into or
embedded in a document. For HTML documents, this includes external
style sheets, included via the HTML LINK element, and inline STYLE
elements. In XML, this includes external style sheets, included via
style sheet processing instructions (see ).