code: def merge(self, options):
          
          if not options:
              return _CallSettings(
                  timeout=self.timeout, retry=self.retry,
                  page_descriptor=self.page_descriptor,
                  page_token=self.page_token,
                  bundler=self.bundler, bundle_descriptor=self.bundle_descriptor,
                  kwargs=self.kwargs)
          else:
              if options.timeout == OPTION_INHERIT:
                  timeout = self.timeout
              else:
                  timeout = options.timeout
  
              if options.retry == OPTION_INHERIT:
                  retry = self.retry
              else:
                  retry = options.retry
  
              if options.page_token == OPTION_INHERIT:
                  page_token = self.page_token
              else:
                  page_token = options.page_token
  
              if options.is_bundling:
                  bundler = self.bundler
              else:
                  bundler = None
  
              if options.kwargs == OPTION_INHERIT:
                  kwargs = self.kwargs
              else:
                  kwargs = self.kwargs.copy()
                  kwargs.update(options.kwargs)
  
              return _CallSettings(
                  timeout=timeout, retry=retry,
                  page_descriptor=self.page_descriptor, page_token=page_token,
                  bundler=bundler, bundle_descriptor=self.bundle_descriptor,
                  kwargs=kwargs)
docs: Returns new _CallSettings merged from this and a CallOptions object.
  
          Note that passing if the CallOptions instance specifies a page_token,
          the merged _CallSettings will have ``flatten_pages`` disabled. This
          permits toggling per-resource/per-page page streaming.
  
          Args:
              options (CallOptions): an instance whose values override
                those in this object. If None, ``merge`` returns a copy of this
                object
  
          Returns:
              CallSettings: The merged settings and options.