code: func (b *Builder) SetMaxReplicaReassignableCount(v int) {
  	if v < 1 {
  		v = 1
  	}
  	if v > 127 {
  		v = 127
  	}
  	b.ring.MaxReplicaReassignableCount = int8(v)
  }
docs: // SetMaxReplicaReassignableCount sets the maximum number of replicas of a
  // partition the builder will set "in motion" during the reassignment wait
  // period.
  //
  // For a full replica use case, you probably want to set this to no more than
  // one less of the majority of replicas so that a majority are always in place
  // at any given time.
  //
  // For an erasure coding use case, you probably want to set this to no more
  // than the number of parity shards so that there are always enough shards in
  // place at any given time.