You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: html.go
    path of file: ./repos/sealer/vendor/github.com/russross/blackfriday/v2
    
    the code of the file until where you have to start completion: //
// Blackfriday Markdown Processor
// Available at http://github.com/russross/blackfriday
//
// Copyright © 2011 Russ Ross <russ@russross.com>.
// Distributed under the Simplified B
    
func NewHTMLRenderer(params HTMLRendererParameters) *HTMLRenderer {
	// configure the rendering engine
	closeTag := htmlClose
	if params.Flags&UseXHTML != 0 {
		closeTag = xhtmlClose
	}

	if params.FootnoteReturnLinkContents == "" {
		// U+FE0E is VARIATION SELECTOR-15.
		// It suppresses automatic emoji presentation of the preceding
		// U+21A9 LEFTWARDS ARROW WITH HOOK on iOS and iPadOS.
		params.FootnoteReturnLinkContents = "<span aria-label='Return'>↩\ufe0e</span>"
	}

	return &HTMLRenderer{
		HTMLRendererParameters: params,

		closeTag:   closeTag,
		headingIDs: make(map[string]int),

		sr: NewSmartypantsRenderer(params.Flags),
	}
}