import java.sql.Statement;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
<BUG>import java.util.stream.Collectors;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.umlg.sqlg.sql.dialect.SqlDialect;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.google.common.base.Preconditions;</BUG>
public class Index implements TopologyInf {

import java.sql.Statement;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;
import static org.umlg.sqlg.structure.SchemaManager.EDGE_PREFIX;
import static org.umlg.sqlg.structure.SchemaManager.VERTEX_PREFIX;
public class Index implements TopologyInf {
