question: public void addIncludeDirectory ( String directory ) throws IOException { if ( ! StringUtils . isEmpty ( directory ) ) { File dir = new File ( directory ) ; if ( ! dir . exists ( ) || ! dir . isDirectory ( ) ) { throw new IOException ( "Invalid include directory: " + dir . getAbsolutePath ( ) ) ; } includeDirectories . add ( dir ) ; } }
target:  adds directory where to search for include files