code: package it.unibz.inf.ontop.dbschema;
  
  import com.google.common.collect.ImmutableSet;
  import it.unibz.inf.ontop.dbschema.impl.json.ConflictingVariableInJoinViewException;
  import it.unibz.inf.ontop.utils.ImmutableCollectors;
  import org.junit.Test;
  
  import static org.junit.Assert.*;
  
  public class ConflictingVariableJoinViewTest {
      private static final String VIEW_FILE = "src/test/resources/fake/join_views_conflicting_column1.json";
      private static final String DBMETADATA_FILE = "src/test/resources/fake/fake.db-extract.json";
  
      public ConflictingVariableJoinViewTest() {
      }
  
      @Test
      public void testPersonUniqueConstraint() throws Exception {
          try {
              LensParsingTest.loadLensesH2(VIEW_FILE, DBMETADATA_FILE);
          } catch (ConflictingVariableInJoinViewException e) {
              assertEquals(
                      e.getConflictingAttributeIds().stream().map(
                              QuotedID::getName).collect(ImmutableCollectors.toSet()),
                      ImmutableSet.of("c_id"));
              return;
          }
          fail();
      }
  }
  