protected void assertDirectory(File file){
  assertExists(file);
  assertTrue("File '" + file.getAbsolutePath() + "' is not a directory",file.isDirectory());
}

protected void assertDirectory ( File file ) { assertExists ( file ) ; assertTrue ( "File '" + file . getAbsolutePath ( ) + "' is not a directory" , file . isDirectory ( ) ) ; }
asserts that a given file exists and is a directory .
