code: def _project_name(self):
          
          name = getattr(self._req.req, 'project_name', '')
          if name:
              return name
          name = getattr(self._req.req, 'name', '')
          if name:
              return safe_name(name)
          raise ValueError('Requirement has no project_name.')
docs: Return the inner Requirement's "unsafe name".
  
          Raise ValueError if there is no name.