     a `{{% CONTENT_TYPE:TEXT }}` pragma tag.
     
         // The strong RenderFunction below wraps a section in a <strong> HTML tag.
-        let strong: RenderFunction = { (info: RenderingInfo, _) -> Rendering? in
-            let rendering = info.tag.render(info.context)
-            return Rendering("<strong>\(rendering!.string)</strong>", .HTML)
+        let strong: RenderFunction = { (info: RenderingInfo) -> Rendering in
+            let rendering = try info.tag.render(info.context)
+            return Rendering("<strong>\(rendering.string)</strong>", .HTML)
         }
 
-        let template = Template(string: "{{#strong}}Hello {{name}}{{/strong}}")!
+        let template = try! Template(string: "{{#strong}}Hello {{name}}{{/strong}}")
         template.registerInBaseContext("strong", Box(strong))
 
         // Renders "<strong>Hello Arthur</strong>"
-        template.render(Box(["name": Box("Arthur")]))!
+        try! template.render(Box(["name": Box("Arthur")]))
     
     - parameter context: The context stack for evaluating mustache tags
     - parameter error:   If there is a problem rendering the tag, upon return

    /**
    The type of the tag: variable or section:
    
        let render: RenderFunction = { (info: RenderingInfo, _) in
            switch info.tag.type {
            case .Variable:
                return Rendering("variable")

    
        // {{# pluralize(count) }}...{{/ }} renders the plural form of the section
        // content if the `count` argument is greater than 1.
        let pluralize = Filter { (count: Int?, info: RenderingInfo) in
            
            // Pluralize the inner content of the section tag:
            var string = info.tag.innerTemplateString
            if count > 1 {
                string += "s"  // naive
            }
            
            return Rendering(string)
        }

        let template = try! Template(string: "I have {{ cats.count }} {{# pluralize(cats.count) }}cat{{/ }}.")
        template.registerInBaseContext("pluralize", Box(pluralize))

        // Renders "I have 3 cats."
        let data = ["cats": ["Kitty", "Pussy", "Melba"]]
        try! template.render(Box(data))
    */
    public let innerTemplateString: String
    
