String removeProperty(String key,String defaultValue){
  if (SysProperties.CHECK && !isKnownSetting(key)) {
    DbException.throwInternalError(key);
  }
  Object x=prop.remove(key);
  return x == null ? defaultValue : x.toString();
}

String removeProperty ( String key , String defaultValue ) { if ( SysProperties . CHECK && ! isKnownSetting ( key ) ) { DbException . throwInternalError ( key ) ; } Object x = prop . remove ( key ) ; return x == null ? defaultValue : x . toString ( ) ; }
remove a string property if it is set and return the value .
