### Question:
TrimDao { public void clear() { try (Connection con = databaseManager.getDataSource().getConnection(); PreparedStatement pstmt = con.prepareStatement("DELETE FROM trim"); ) { pstmt.executeUpdate(); } catch (SQLException e) { throw new RuntimeException(e.toString(), e); } } @Inject  TrimDao(DatabaseManager databaseManager); TrimEntry save(TrimEntry trimEntry); TrimEntry get(); void clear(); int count();  }### Answer:
@Test void testClear() { dao.clear(); int count = dao.count(); assertEquals(0, count); assertNull(dao.get()); }