code: def _sitelist(self, matrix):
          
          _list = []
          for item in matrix:
              sites = []
  
              if isinstance(matrix[item], list):
                  sites = matrix[item]
              elif isinstance(matrix[item], dict):
                  sites = matrix[item]['site']
  
              for site in sites:
                  if len(site.keys()) > 4:  # closed, fishbowl, private
                      continue
                  domain = self.params.get('domain')
                  if domain:
                      if domain in site['url']:
                          _list.append(site['url'])
                  else:
                      _list.append(site['url'])
  
          return _list
docs: Returns a list of sites from a SiteMatrix, optionally filtered
          by 'domain' param