protected String getTestDataMigrationLocation() {
        Objects.requireNonNull(testDataDir);

        if (!Files.isDirectory(testDataDir)) {
            throw new RuntimeException(LogUtil.message("Can't find directory {}",
                    testDataDir.normalize().toAbsolutePath().toString()));
        }
        return FILE_SYSTEM_LOCATION_PREFIX + testDataDir.normalize().toAbsolutePath();
    }
@return The location of the migration containing the test data.
See {@link org.flywaydb.core.api.configuration.FluentConfiguration#locations(String...)}
stroom-test-common/src/main/java/stroom/test/common/util/db/AbstractSingleFlywayMigrationTest.java