def pfmerge(self, dest, *sources):
sources = [self.redis_key(k) for k in sources]<EOL>with self.pipe as pipe:<EOL><INDENT>return pipe.pfmerge(self.redis_key(dest), *sources)<EOL><DEDENT>
Merge N different HyperLogLogs into a single one.

:param dest:
:param sources:
:return: