用什么代替php 5.2中的命名空间

What do I use in place of namespace for older versions of php 5.2 and earlier using this code below it gives an error Parse error: syntax error, unexpected T_STRING

<?php

namespace Aws\Tests\CloudWatch;

use Aws\CloudSearch\CloudSearchClient;

class CloudSearchClientTest extends \Guzzle\Tests\GuzzleTestCase
{
    /**
     * @covers Aws\CloudSearch\CloudSearchClient::factory
     */
    public function testFactoryInitializesClient()
    {
        $client = CloudSearchClient::factory(array(
            'key'    => 'foo',
            'secret' => 'bar',
            'region' => 'us-east-1'
        ));

        $this->assertInstanceOf('Aws\Common\Signature\SignatureV4', $this->readAttribute($client, 'signature'));
        $this->assertInstanceOf('Aws\Common\Credentials\Credentials', $client->getCredentials());
        $this->assertEquals('https://cloudsearch.us-east-1.amazonaws.com', $client->getBaseUrl());
    }
}

The code you're trying to use here (looks like the Amazon AWS SDK?) is not compatible with PHP 5.2. You will need to upgrade to PHP 5.3 or later to use it.

I guess you just cannot use these namespaced classes in php 5.2 code.