code: func InitializeOptions(opts *Options) *Options {
  	if opts == nil {
  		opts = &Options{}
  	}
  
  	if opts.Extension == "" {
  		opts.Extension = defaultExtension
  	}
  
  	if opts.DelimLeft == "" {
  		opts.DelimLeft = defaultDelimLeft
  	}
  
  	if opts.DelimRight == "" {
  		opts.DelimRight = defaultDelimRight
  	}
  
  	if opts.AttributeNameClass == "" {
  		opts.AttributeNameClass = defaultAttributeNameClass
  	}
  	if opts.NoCloseTagNames == nil {
  		opts.NoCloseTagNames = make([]string, len(defaultNoCloseTagNames))
  		copy(opts.NoCloseTagNames, defaultNoCloseTagNames)
  	}
  
  	if opts.Indent != "" {
  		opts.formatter = newFormatter(opts.Indent)
  	}
  
  	return opts
  }
docs: // InitializeOptions initializes the options.