Process a line of metadata found in the markdown.

		Lines are usually in the format of "key: value".

		Modify the kwargs dict in order to change or add new kwargs that should
		be passed to the class's constructor.

def process_meta(cls, line, kwargs):
		"""
		Process a line of metadata found in the markdown.

		Lines are usually in the format of "key: value".

		Modify the kwargs dict in order to change or add new kwargs that should
		be passed to the class's constructor.
		"""
		if line.startswith('slug:'):
			kwargs['slug'] = line[5:].strip()

		elif line.startswith('public:'):
			try:
				kwargs['public'] = _str_to_bool(line[7:])
			except ValueError:
				LOG.warning('invalid boolean value for public', exc_info=True)

		elif line.startswith('private:'):
			try:
				kwargs['public'] = not _str_to_bool(line[8:])
			except ValueError:
				LOG.warning('invalid boolean value for private', exc_info=True)