public void setPluginAggregationFunctions(
     List<ConfigurationPlugInAggregationFunction> aggregationfunctions) {
   for (ConfigurationPlugInAggregationFunction aggrefn : aggregationfunctions) {
     if (aggrefn.getFactoryClassName() != null)
       m_esperconfig.addPlugInAggregationFunctionFactory(
           aggrefn.getName(), aggrefn.getFactoryClassName().toString());
   }
 }
 @Override
 public void addPlugInAggregationFunctionFactory(String arg0, String arg1)
     throws ConfigurationException {
   m_esperconfig.addPlugInAggregationFunctionFactory(arg0, arg1);
 }