docs: def __indent(self, lines, indent, initial=2):
  		"""This will indent the given set of lines by normal HTML layout.
  		An initial indent of `2*indent` will be used to account for the
  		`<html><head>` or `<html><body>` levels."""
  		tagempty = re.compile(r"""<\w+(\s+[^>]*?)*/>""")
  		tagopen = re.compile(r"""<\w+(\s+[^>]*?)*>""")
  		tagclose = re.compile(r"""</\w+\s*>""")
  		prefix = indent * initial
  		for i in range(len(lines)):
  			line = lines[i].strip()
  			if tagempty.match(line):
  				line = prefix + line
  			elif tagopen.match(line):
  				line = prefix + line
  				prefix = prefix + indent
  			elif tagclose.match(line):
  				prefix = prefix[:-len(indent)]
  				line = prefix + line
  			elif '\n' in line:
  				line = [prefix + l.strip() for l in line.split('\n')]
  				line = os.linesep.join(line)
  			else:
  				line = prefix + line
  			lines[i] = line + os.linesep