code: package it.unibz.inf.ontop.rdf4j.repository;
  
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  
  import java.io.IOException;
  import java.sql.SQLException;
  
  import static org.junit.Assert.assertEquals;
  
  public class RDF4JMetaMappingTest extends AbstractRDF4JTest {
  
      private static final String R2RML_FILE = "/meta/meta-mapping.ttl";
      private static final String SQL_SCRIPT = "/meta/meta-create.sql";
  
      @BeforeClass
      public static void before() throws IOException, SQLException {
          initR2RML(SQL_SCRIPT, R2RML_FILE);
      }
  
      @AfterClass
      public static void after() throws SQLException {
          release();
      }
      @Test
      public void testSPO() {
          int count = runQueryAndCount("SELECT * WHERE {?s ?p ?o .}");
          assertEquals(4, count); // VALi :a testClass & VALi :a VALi, for i = 1, 2
      }
  }