The command provides a list of replica nodes replicating from the specified
master node. The list is provided in the same format used by `CLUSTER NODES`
(please refer to its documentation for the specification of the format).

The command will fail if the specified node is not known or if it is not a
master according to the node table of the node receiving the command.

Note that if a replica is added, moved, or removed from a given master node, and
we ask `CLUSTER REPLICAS` to a node that has not yet received the configuration
update, it may show stale information. However eventually (in a matter of
seconds if there are no network partitions) all the nodes will agree about the
set of nodes associated with a given master.

@return

The command returns data in the same format as `CLUSTER NODES`.
