code: def to_str(self):
          '''Convert to string.'''
          pairs = []
          for name, value in self.get_all():
              if value and self._wrap_width:
                  pairs.append('{0}:{1}'.format(
                      name,
                      '\r\n'.join(textwrap.wrap(
                          value, width=self._wrap_width,
                          drop_whitespace=False, initial_indent=' ',
                          subsequent_indent=' '
                      ))
                  ))
              elif value:
                  pairs.append('{0}: {1}'.format(name, value))
              else:
                  pairs.append('{0}:'.format(name))
  
          pairs.append('')
          return '\r\n'.join(pairsf to_str(self):
          '''Convert to string.'''
          pairs = []
          for name, value in self.get_all():
              if value and self._wrap_width:
                  pairs.append('{0}:{1}'.format(
                      name,
                      '\r\n'.join(textwrap.wrap(
                          value, width=self._wrap_width,
                          drop_whitespace=False, initial_indent=' ',
                          subsequent_indent=' '
                      ))
                  ))
              elif value:
                  pairs.append('{0}: {1}'.format(name, value))
              else:
                  pairs.append('{0}:'.format(name))
  
          pairs.append('')
          return '\r\n'.join(pairs)
docs: Convert to string.