code: public static Path getDefaultWriterFilePath(State state, int numBranches, int branchId) {
      if (state instanceof WorkUnitState) {
        WorkUnitState workUnitState = (WorkUnitState) state;
        return new Path(ForkOperatorUtils.getPathForBranch(workUnitState, workUnitState.getOutputFilePath(),
            numBranches, branchId));
      } else if (state instanceof WorkUnit) {
        WorkUnit workUnit = (WorkUnit) state;
        return new Path(ForkOperatorUtils.getPathForBranch(workUnit, workUnit.getOutputFilePath(),
            numBranches, branchId));
      }
  
      throw new RuntimeException("In order to get the default value for " + ConfigurationKeys.WRITER_FILE_PATH
          + " the given state must be of type " + WorkUnitState.class.getName() + " or " + WorkUnit.class.getName());
    }
docs: Creates the default {@link Path} for the {@link ConfigurationKeys#WRITER_FILE_PATH} key.
  @param numBranches is the total number of branches for the given {@link State}.
  @param branchId is the id for the specific branch that the {@link org.apache.gobblin.writer.DataWriter} will write to.
  @return a {@link Path} specifying the directory where the {@link org.apache.gobblin.writer.DataWriter} will write to.