     /// - Parameters:
     ///   - textView: the textview that is requesting the image
     ///   - attachment: the attachment that does not an have image source
+    ///
     /// - Returns: an UIImage to represent the attachment graphically
-    func textView(_ textView: TextView,
-                  placeholderForAttachment attachment: NSTextAttachment) -> UIImage
+    ///
+    func textView(_ textView: TextView, placeholderFor attachment: NSTextAttachment) -> UIImage
 
     /// Called after a attachment is removed from the storage.
     ///

    ///     - success: when the image is obtained, this closure should be executed.
    ///     - failure: if the image cannot be obtained, this closure should be executed.
    ///
    /// - Returns: the placeholder for the requested image.  Also useful if showing low-res versions
    ///         of the images.
    ///
    func textView(_ textView: TextView,
                  attachment: NSTextAttachment,
                  imageAt url: URL,
                  onSuccess success: @escaping (UIImage) -> Void,
                  onFailure failure: @escaping () -> Void) -> UIImage

    /// Called when an attachment is about to be added to the storage as an attachment (copy/paste), so that the
    /// delegate can specify an URL where that attachment is available.

        attachment: NSTextAttachment,
        imageFor url: URL,
        onSuccess success: @escaping (UIImage) -> (),
        onFailure failure: @escaping () -> ()) {
        
        guard let textAttachmentDelegate = textAttachmentDelegate else {
            fatalError("This class requires a text attachment delegate to be set.")
        }
        
        textAttachmentDelegate.textView(self, attachment: attachment, imageAt: url, onSuccess: success, onFailure: failure)
    }

    func storage(_ storage: TextStorage, placeholderFor attachment: NSTextAttachment) -> UIImage {
        guard let textAttachmentDelegate = textAttachmentDelegate else {
            fatalError("This class requires a text attachment delegate to be set.")
        }

        return textAttachmentDelegate.textView(self, placeholderFor: attachment)
    }
    
    func storage(_ storage: TextStorage, urlFor imageAttachment: ImageAttachment) -> URL {
