def clean_tag_borders(string)
      result = string.gsub(/\s?\*{2,}.*?\*{2,}\s?/) do |match|
        preserve_border_whitespaces(match, default_border: ReverseMarkdown.config.tag_border) do
          match.strip.sub('** ', '**').sub(' **', '**')
        end
      end

      result = result.gsub(/\s?\_{2,}.*?\_{2,}\s?/) do |match|
        preserve_border_whitespaces(match, default_border: ReverseMarkdown.config.tag_border) do
          match.strip.sub('__ ', '__').sub(' __', '__')
        end
      end

      result = result.gsub(/\s?~{2,}.*?~{2,}\s?/) do |match|
        preserve_border_whitespaces(match, default_border: ReverseMarkdown.config.tag_border) do
          match.strip.sub('~~ ', '~~').sub(' ~~', '~~')
        end
      end

      result.gsub(/\s?\[.*?\]\s?/) do |match|
        preserve_border_whitespaces(match) do
          match.strip.sub('[ ', '[').sub(' ]', ']')
        end
      end
    end
def clean_tag_borders(string)
      result = string.gsub(/\s?\*{2,}.*?\*{2,}\s?/) do |match|
        preserve_border_whitespaces(match, default_border: ReverseMarkdown.config.tag_border) do
          match.strip.sub('** ', '**').sub(' **', '**')
        end
      end

      result = result.gsub(/\s?\_{2,}.*?\_{2,}\s?/) do |match|
        preserve_border_whitespaces(match, default_border: ReverseMarkdown.config.tag_border) do
          match.strip.sub('__ ', '__').sub(' __', '__')
        end
      end

      result = result.gsub(/\s?~{2,}.*?~{2,}\s?/) do |match|
        preserve_border_whitespaces(match, default_border: ReverseMarkdown.config.tag_border) do
          match.strip.sub('~~ ', '~~').sub(' ~~', '~~')
        end
      end

      result.gsub(/\s?\[.*?\]\s?/) do |match|
        preserve_border_whitespaces(match) do
          match.strip.sub('[ ', '[').sub(' ]', ']')
        end
      end
    end
Find non-asterisk content that is enclosed by two or
 more asterisks. Ensure that only one whitespace occurs
 in the border area.
 Same for underscores and brackets.