question: private void determineHostsAsProperty ( ) { if ( hosts . startsWith ( "${" ) && hosts . endsWith ( "}" ) ) { String hostsProperty = hosts . substring ( 2 , hosts . length ( ) - 1 ) ; hosts = PropertyUtil . getProperty ( hostsProperty ) ; if ( hosts == null ) { throw new IllegalArgumentException ( "Could not find property '" + hostsProperty + "'" ) ; } } }
target:  sets hosts if the _hosts propertey is determined to be a property placeholder Throws IllegalArgumentException argument exception when nothing found