/// <summary>
        /// Creates Code from tree
        /// </summary>
        /// <param name="tree">The tree</param>
        /// <param name="ret">Return value</param>
        /// <param name="parameters">Parameters</param>
        /// <param name="variables">Variables</param>
        /// <param name="initializers">Initializers</param>
        /// <returns>List of code</returns>
        public override IList <string> CreateCode(ObjectFormulaTree tree, string ret,
                                                  string[] parameters, out IList <string> variables, out IList <string> initializers)
        {
            /* !!!
             * if (tree.Operation is OptionalOperation)
             * {
             *  variables = null;
             *  initializers = null;
             *  return null;
             * }
             * //*/
            string[] sep = separatorCreator[tree];
            if (sep == null)
            {
                variables    = null;
                initializers = null;
                return(null);
            }
            List <string> l  = new List <string>();
            string        tt = TypeCreator.GetType(tree.ReturnType);
            string        st = "";

            if (!tt.Equals("object"))
            {
                st = "(" + tt + ")";
            }
            string sp = ret.Substring(4);
            int    k  = int.Parse(sp);

            if (sep.Length == 2)
            {
                string[] ss = new string[] { " = measurement", ".Parameter();" };
                if (sep[0].Equals(ss[0]) & sep[1].Equals(ss[1]))
                {
                    initializers = new List <string>()
                    {
                        "measurement" + sp + " = " +
                        "DataPerformer.Formula.StaticExtensionDataPerformerFormula.ToMeasurement(trees["
                        + k + "]);"
                    };
                    variables = new List <string>()
                    {
                        "DataPerformer.Interfaces.IMeasurement measurement" + sp + ";"
                    };
                    string str = ret + " = " + st + "measurement" + sp + sep[1];
                    return(new List <string>()
                    {
                        str
                    });
                }
                if (sep[0].Equals(" = aliasName") & sep[1].Equals(".Value;"))
                {
                    string str = ret + " = " + st + "aliasName" + sp + sep[1];
                    initializers = new List <string>()
                    {
                        "aliasName" + sp + " = " +
                        "DataPerformer.Formula.StaticExtensionDataPerformerFormula.ToAliasName(trees["
                        + k + "]);"
                    };
                    variables = new List <string>()
                    {
                        "Diagram.UI.Interfaces.IAliasName aliasName" + sp + ";"
                    };
                    return(new List <string>()
                    {
                        str
                    });
                }
            }
            variables    = new List <string>();
            initializers = new List <string>();

            string s = ret;
            int    n = sep.Length;
            int    m = parameters.Length;

            for (int i = 0; i < n; i++)
            {
                s += sep[i];
                if (i < m)
                {
                    s += parameters[i];
                }
            }
            l.Add(s);
            return(l);
        }