}
public void test_toString() throws Exception {
DruidPooledConnection conn = dataSource.getConnection();
DruidConnectionHolder holder = conn.getConnectionHolder();
Field field = DruidConnectionHolder.class.getDeclaredField("statementPool");
field.setAccessible(true);
Assert.assertNull(field.get(holder));
holder.toString();
Assert.assertNull(field.get(holder));
holder.getStatementPool();
Assert.assertNotNull(field.get(holder));
holder.toString();
PreparedStatement stmt = conn.prepareStatement("select 1");
stmt.execute();
stmt.close();
conn.close();
Assert.assertEquals(1, holder.getStatementPool().size());
holder.toString();
}