修改sphinxapi.php并在Sphinx上重启

我应该改变sphinxapi.php，我的sphinxapi.php上(usr/local/sphinx/lib/sphinxapi.php)我改变了它，但我应该怎么做之后使用新的函数?

my PHP:

<?php
            $sphinx = new SphinxClient();
            $sphinx->SetServer($this->config->sphinx->host, $this->config->sphinx->port);
            $sphinx->SetMatchMode(SPH_MATCH_ALL);
            $sphinx->SetLimits(0, 1,1);
..filters...
            $sphinx->RemoveFilter($color['id']);

我的新功能:

 function RemoveFilter ( $attribute )
   {
      assert ( is_string($attribute) );
      foreach($this->_filters AS $key => $filter){
         if($filter['attr'] == $attribute){
            unset($this->_filters[$key]);
            break;
         }
      }
   }

错误:

Fatal error: Call to undefined method SphinxClient::RemoveFilter() in