DataDictionary.Interpreter.Call.GetPlaceHolders C# (CSharp) Method

        private List<Parameter> GetPlaceHolders(Function function, Dictionary<Actual, IValue> parameterValues)
        {
            List<Parameter> retVal = new List<Parameter>();

            foreach (KeyValuePair<Actual, IValue> pair in parameterValues)
            {
                Actual actual = pair.Key;

                PlaceHolder placeHolder = pair.Value as PlaceHolder;
                if (placeHolder != null && actual.Parameter.Enclosing == function)
                {
                    retVal.Add(actual.Parameter);
                }
            }

            if (retVal.Count != parameterValues.Count || retVal.Count == 0)
            {
                retVal = null;
            }

            return retVal;
        }