private String getUniqueName() {
    return UUID.randomUUID().toString().replaceAll("-", "");
  }
@param conn         the HBase cluster connection
@param tableName    the table name of the table to load into
@param pool         the ExecutorService
@param queue        the queue for LoadQueueItem
@param startEndKeys start and end keys
@return A map that groups LQI by likely bulk load region targets and Set of missing hfiles.
hbase-server/src/main/java/org/apache/hadoop/hbase/tool/BulkLoadHFilesTool.java