code: def first(self):
          
          if len(self):
              self._params.update(limit=1)
              if 'filter' not in self._params:
                  return list(self)[0]
              else: # Filter may not return results
                  result = list(self)
                  if result:
                      return result[0]
docs: Returns the first object matched or None if there is no
          matching object.
          ::
                  
              >>> iterator = Host.objects.iterator()
              >>> c = iterator.filter('kali')
              >>> if c.exists():
              >>>    print(c.count())
              >>>    print(c.first())
              7
              Host(name=kali67)
          
          If results are not needed and you only 1 result, this can be called
          from the CollectionManager::
          
              >>> Host.objects.first()
              Host(name=SMC)
          
          :return: element or None