docs: def _get_full_title(self):
          """Determines the title for the need in order of precedence:
          directive argument, first sentence of requirement (if
          `:title_from_content:` was set, and '' if no title is to be derived."""
          if len(self.arguments) > 0:  # a title was passed
              if 'title_from_content' in self.options:
                  self.log.warning(
                      'Needs: need "{}" has :title_from_content: set, '
                      'but a title was provided. (see file {})'
                          .format(self.arguments[0], self.docname)
                  )
              return self.arguments[0]
          elif self.title_from_content:
              first_sentence = ' '.join(self.content).split('.', 1)[0]
              if not first_sentence:
                  raise NeedsInvalidException(':title_from_content: set, but '
                                              'no content provided. '
                                              '(Line {} of file {}'
                                              .format(self.lineno, self.docname))
              return first_sentence
          else:
              return ''