code: def replace_evict_func(self, func, only_read=False):
          
          self.logger.info('Replace the evict function %s ---> %s' % (
              get_function_signature(self.evict_func), get_function_signature(func)))
          self.evict_func = func
          return True
docs: >>> cache = Cache(log_level=logging.WARNING)
          >>> def evict(dict, evict_number=10): pass
          >>> cache.replace_evict_func(evict)
          True
          >>> def evict_b(dict): pass
          >>> cache.replace_evict_func(evict_b)
          False
          >>> def evict_c(dict, a, b): pass
          >>> cache.replace_evict_func(evict_c)
          False