List messages = compiler.compile( compilerConfig );
List messages = new ArrayList();  for ( Iterator it = getCompilerConfigurations().iterator(); it.hasNext(); ) { CompilerConfiguration compilerConfig = (CompilerConfiguration) it.next();  compiler = (Compiler) lookup( Compiler.ROLE, getRoleHint() );  messages.addAll( compiler.compile( compilerConfig ) ); }  int numCompilerErrors = compilerErrorCount( messages );  int numCompilerWarnings = messages.size() - numCompilerErrors;
    public void testCompilingSources()        throws Exception    {        List messages = compiler.compile( compilerConfig );        assertEquals( "Wrong number of compilation errors.",                      expectedErrors(),                      compilerErrorCount( messages ) );    }