code: def add_to_stage(self, paths):
          
          cmd = self._command.add(paths)
  
          (code, stdout, stderr) = self._exec(cmd)
  
          if code:
              raise errors.VCSError('Can\'t add paths to VCS. Process exited with code %d and message: %s' % (
                  code, stderr + stdout))
docs: Stage given files
  
          :param paths:
          :return: