code: @Override
      public synchronized void close() {
          try {
  
              for (final PreparedStatementCapsule preparedStatement : stmts.values()) {
                  try {
                      preparedStatement.ps.close();
                  } catch (final SQLException e) {
                      logger.warn("Could not close statement.", e);
                  }
              }
  
              stmts.clear();
  
              entities.forEach((key, mappedEntity) -> closeMappedEntity(mappedEntity));
  
              if (properties.isSchemaPolicyCreateDrop()) {
                  dropAllEntities();
              }
  
              conn.close();
              logger.debug("Connection to database closed");
  
          } catch (final SQLException ex) {
              logger.warn("Unable to close connection", ex);
          }
      }
docs: Closes the connection to the database.