code: public static String getSourceByClass(Class<?> koanClass) {
  
          File file = new File(getKoanFileLocation(koanClass));
     		StringBuilder contents = new StringBuilder();
     		BufferedReader reader = null;
  
     		try {
     			reader = new BufferedReader(new FileReader(file));
     			String text = null;
  
     			while ((text = reader.readLine()) != null) {
     				contents.append(text).append(System.lineSeparator());
     			}
     		} catch (IOException e) {
     			e.printStackTrace();
     		} finally {
     			try {
     				if (reader != null) {
     					reader.close();
     				}
     			} catch (IOException e) {
     				e.printStackTrace();
     			}
     		}
     		return contents.toString();
     	}
docs: Gets source for a class.
  
  @param koanClass the koan class
  @return the source code as a string