code: private static List<String> parseAndCompare(List<String> fileNames, int masterPartitionId) {
          List<String> sourceFileNames = new ArrayList<String>();
          for(String fileName: fileNames) {
              String[] partitionIdReplicaChunk = fileName.split(SPLIT_LITERAL);
              if(Integer.parseInt(partitionIdReplicaChunk[0]) == masterPartitionId) {
                  sourceFileNames.add(fileName);
              }
          }
          return sourceFileNames;
      }
docs: This method take a list of fileName of the type partitionId_Replica_Chunk
  and returns file names that match the regular expression
  masterPartitionId_