code: public final void debug(Object message, Throwable t) {
          if (isLevelEnabled(LOG_LEVEL_DEBUG)) {
              log(LOG_LEVEL_DEBUG, message, t);
          }
      }
docs: Logs a message with
  <code>org.apache.commons.logging.impl.SimpleLog.LOG_LEVEL_DEBUG</code>.
  
  @param message to log
  @param t       log this cause
  
  @see Log#debug(Object, Throwable)