// add NotFunction
targetFunctions.addAll((new NotFunctionCluster()).getSupportedFunctions());
// add ComparisonFunction
targetFunctions.addAll((new ComparisonFunctionCluster()).getSupportedFunctions());
// add MatchFunction
targetFunctions.addAll((new MatchFunctionCluster()).getSupportedFunctions());
targetAbstractFunctions = new HashMap<URI, MapFunctionProxy>();
}