code: public String getFileName(State properties) {
  
      String extension =
          this.format.equals(WriterOutputFormat.OTHER) ? getExtension(properties) : this.format.getExtension();
      String fileName = WriterUtils.getWriterFileName(properties, this.branches, this.branch, this.writerId, extension);
  
      if (this.partition.isPresent()) {
        fileName = getPartitionedFileName(properties, fileName);
      }
  
      List<StreamCodec> encoders = getEncoders();
      if (!encoders.isEmpty()) {
        StringBuilder filenameBuilder = new StringBuilder(fileName);
        for (StreamCodec codec : encoders) {
          filenameBuilder.append('.');
          filenameBuilder.append(codec.getTag());
        }
  
        fileName = filenameBuilder.toString();
      }
  
      return fileName;
    }
docs: Get the file name to be used by the writer. If a {@link org.apache.gobblin.writer.partitioner.WriterPartioner} is used,
  the partition will be added as part of the file name.