def matching_text_element_lines(re, exclude_nested=[:a])
      matches = []
      find_type_elements_except(:text, exclude_nested).each do |e|
        first_line = e.options[:location]
        # We'll error out if kramdown doesn't have location information for
        # the current element. It's better to just not match in these cases
        # rather than crash.
        next if first_line.nil?
        lines = e.value.split("\n")
        lines.each_with_index do |l, i|
          matches << first_line + i if re.match(l)
        end
      end
      matches
    end
def matching_text_element_lines(re, exclude_nested=[:a])
      matches = []
      find_type_elements_except(:text, exclude_nested).each do |e|
        first_line = e.options[:location]
        # We'll error out if kramdown doesn't have location information for
        # the current element. It's better to just not match in these cases
        # rather than crash.
        next if first_line.nil?
        lines = e.value.split("\n")
        lines.each_with_index do |l, i|
          matches << first_line + i if re.match(l)
        end
      end
      matches
    end
Returns line numbers for lines that match the given regular expression.
 Only considers text inside of 'text' elements (i.e. regular markdown
 text and not code/links or other elements).