Migrating an array of values into multiple entities

Here's the custom plugin I ended up writing:

<?php

namespace Drupal\mymodule\Plugin\migrate\process;

use Drupal\migrate\MigrateExecutableInterface;
use Drupal\migrate\Row;
use Drupal\migrate_plus\Plugin\migrate\process\EntityGenerate;
use Drupal\migrate_plus\Plugin\migrate\process\EntityLookup;

/**
 * This plugin generates district entities within the process plugin.
 *
 * @MigrateProcessPlugin(
 *   id = "district_generate"
 * )
 *
 * @see EntityGenerate
 *
 * @code
 * process:
 *   field_political_district:
 *     plugin: district_generate
 *     source: jurisdiction
 *     district_set_name: constants/ABC
 *     district_set_value: "@_district_set"
 *     prefix: "District"
 *     ... other entityGenerate config
 * @endcode
 */
class DistrictGenerate extends EntityGenerate {

  /**
   * {@inheritdoc}
   */
  public function transform($value, MigrateExecutableInterface $migrateExecutable, Row $row, $destinationProperty) {
    $this->row = $row;
    $this->migrateExecutable = $migrateExecutable;
    $name = $value;
    if (isset($this->configuration['district_set_name'])) {
      $suffix = $row->get($this->configuration['district_set_name']);
      $name = $name . ', ' . $suffix;
    }
    // Creates an entity if the lookup determines it doesn't exist.
    if (!($result = EntityLookup::transform($name, $migrateExecutable, $row, $destinationProperty))) {
      if (isset($this->configuration['district_set_value'])) {
        $this->configuration['values']['field_district_set'] = $this->configuration['district_set_value'];
      }
      $prefix = $this->configuration['prefix'] ?? 'District';
      $this->configuration['default_values']['field_display_name'] = $prefix . ' ' . $value;
      $result = $this->generateEntity($name);
    }
    return $result;
  }

}