setRepopulateThreshold

 import com.screenscraper.util.*;

 // Create a new ProxyServerPool object.
 proxyServerPool = new ProxyServerPool();

 // Must be set on the session before other calls are made
 session.setProxyServerPool(proxyServerPool);

 // This tells the pool to populate itself from a file
 proxyServerPool.populateFromFile( "proxies.txt" );

 // Validate proxies up to 25 proxies at a time.
 proxyServerPool.setNumProxiesToValidateConcurrently( 25 );

 // Set timout interval
 proxyServerPool.filter( 7 );

 // Write good proxies to file
 proxyServerPool.writeProxyPoolToFile( "good_proxies.txt" );

 // Write Proxy Servers to log
 proxyServerPool.outputProxyServersToLog();

 // As a scraping session runs, screen-scraper will filter out
 // proxies that become non-responsive. If the number of proxies
 // gets down to a specified level, screen-scraper can repopulate
 // itself. Thats what this method call controls.

 proxyServerPool.setRepopulateThreshold( 5 );