question: private void validateReplicaAvailability ( Slice slice , String shard , String collectionName , int count ) { if ( slice != null ) { Collection < Replica > allReplicasForShard = slice . getReplicas ( ) ; if ( allReplicasForShard == null ) { throw new SolrException ( SolrException . ErrorCode . BAD_REQUEST , "No replicas found  in shard/collection: " + shard + "/" + collectionName ) ; } if ( allReplicasForShard . size ( ) == 1 ) { throw new SolrException ( SolrException . ErrorCode . BAD_REQUEST , "There is only one replica available in shard/collection: " + shard + "/" + collectionName + ". Cannot delete that." ) ; } if ( allReplicasForShard . size ( ) <= count ) { throw new SolrException ( SolrException . ErrorCode . BAD_REQUEST , "There are lesser num replicas requested to be deleted than are available in shard/collection : " + shard + "/" + collectionName + " Requested: " + count + " Available: " + allReplicasForShard . size ( ) + "." ) ; } } }
target:  Validate if there is less replicas than requested to remove. Also error out if there is only one replica available