code: public void applyProperties(Map properties) {
          if (properties.containsKey("enabled")) {
              setEnabled(!"false".equalsIgnoreCase
                         ((String)properties.get("enabled")));
          }
  
          if (properties.containsKey("debug")) {
              setDebugEnabled(!"false".equalsIgnoreCase
                              ((String)properties.get("debug")));
          }
  
          if (properties.containsKey("info")) {
              setInfoEnabled(!"false".equalsIgnoreCase
                             ((String)properties.get("info")));
          }
  
          if (properties.containsKey("warn")) {
              setWarnEnabled(!"false".equalsIgnoreCase
                             ((String)properties.get("warn")));
          }
  
          if (properties.containsKey("error")) {
              setErrorEnabled(!"false".equalsIgnoreCase
                              ((String)properties.get("error")));
          }
      }
docs: Understands and applies the following boolean properties. True is the
  default value if the value doesn't equal "false", ignoring case.
  
  <ul>
  <li>enabled
  <li>debug
  <li>info
  <li>warn
  <li>error
  </ul>