where is org.apache.solr.servlet.SolrServlet class

[????????]

Hi All,
  
 Anyone can tell me where is the class org.apache.solr.servlet.SolrServlet ?
 I have checked out the lucene source  code from the path 
http://svn.apache.org/repos/asf/lucene/dev/trunk , however I can not find it in 
this path .
 Thanks
  
  
  
  
 Best Regards,
 Guoan Hu