/// <summary>
        /// Creates a grammar file representing all of the main grammars of the grammar providers
        /// to the file requested.
        /// </summary>
        /// <param name="fileToSaveTo">File to save the main grammar to.</param>
        public void UpdateMainGrammarFile(String fileToSaveTo)
        {
            List <String>     rules    = new List <string>();
            List <XmlElement> elements = new List <XmlElement>();

            // Add grammars from all of our grammar providers.
            foreach (GrammarProvider provider in _grammarProviders)
            {
                if (provider.MainGrammar != null)
                {
                    rules.Add(provider.MainGrammar.RuleName);
                    elements.AddRange(provider.MainGrammar.Rules);
                }
            }

            // Add utility rules.
            foreach (String fileName in _utilityFiles)
            {
                XmlDocument fileDoc = new XmlDocument();
                fileDoc.Load(fileName);
                foreach (XmlElement element in fileDoc.LastChild.ChildNodes)
                {
                    elements.Add(element);
                }
            }

            XmlDocument doc = new XmlDocument();

            doc.AppendChild(doc.CreateNode(XmlNodeType.XmlDeclaration, "", ""));

            XmlElement grammar = GrammarUtility.CreateElement(doc, "grammar", new Dictionary <String, String>
            {
                { "version", "1.0" },
                { "xml:lang", "en-US" },
                { "mode", "voice" },
                { "root", "overallCommand" },
                { "tag-format", "semantics/1.0" },
            });
            XmlElement overallRule = GrammarUtility.CreateElement(doc, "rule", new Dictionary <String, String>
            {
                { "id", "overallCommand" },
                { "scope", "public" },
            });
            XmlElement samiRule = GrammarUtility.CreateElement(doc, "item", new Dictionary <String, String>());

            samiRule.InnerText = "Sammie";
            overallRule.AppendChild(samiRule);

            overallRule.AppendChild(GrammarUtility.CreateListOfRuleRefs(doc, rules));
            grammar.AppendChild(overallRule);

            GrammarUtility.CopyElementsToNewRule(grammar, elements);
            doc.AppendChild(grammar);
            doc.Save(fileToSaveTo);
        }