migrate.api.php in core/modules/migrate/migrate.api.php
Hooks provided by the Migrate module.
migrate_prepare_row_test.module in core/modules/migrate/tests/modules/migrate_prepare_row_test/migrate_prepare_row_test.module
Test module for testing the migration source plugin prepareRow() exception handling.
MigrationLookupTest.php in core/modules/migrate/tests/src/Unit/process/MigrationLookupTest.php
MigrationTest.php in core/modules/migrate/tests/src/Unit/MigrationTest.php
Contains \Drupal\Tests\migrate\Unit\MigrationTest.
MigrationTest.php in core/modules/migrate/tests/src/Unit/process/MigrationTest.php
SourcePluginBase.php in core/modules/migrate/src/Plugin/migrate/source/SourcePluginBase.php