import java.io.*;
import java.util.*;
import java.util.regex.*;

import org.codehaus.plexus.util.*;

File buildFile = new File( basedir, "build.xml" );
System.out.println( "Checking for existence of " + buildFile );
if ( !buildFile.isFile() )
{
    throw new IllegalStateException( "Custom build.xml was deleted!" );
}

return true;