anchor.diff:  ### Flashcard (FlashcardWithoutId)
   + id: `12345678-9012-3456-7890-123456789012` (string, required) - Flashcard UUID, 36 chars, 8-4-4-4-12 chars
   + deckId: `291acb97-6f50-4522-8049-aee0b4e16b42` (string, required) - Deck UUID, 36 chars, 8-4-4-4-12 chars
  ++ questionImageURL: `http://www.sourcecertain.com/img/Example.png` (string, optional) - URL to image attached to this flashcard
  ++ answerImageURL: `http://www.sourcecertain.com/img/Example.png` (string, optional) - URL to image attached to this flashcard
   
   ### TipWithoutId (object)
   + essence: `Sample content` (string, required) - content of a Tip
  
positive.code:         AAAAAAAAAAAAAAAAAAAAAP/EABQRAQAAAAAAAAAAAAAAAAAAAAD/2gAMAwEAAhEDEQA/AL+AD//Z
          -----BOUNDARY
  
  
  
  # Group Tip
  
  
negative.code: + Response 200 (application/json)
      + Attributes (FlashcardCollection)
  
  ### Add image as question [POST /decks/{deckId}/flashcards{flashcardId}/questionImage]
  + Request (multipart/form-data; boundary=---BOUNDARY)
  
          -----BOUNDARY
          Content-Disposition: form-data; name="file"; filename="image.jpg"
          Content-Type: image/jpeg
          Content-Transfer-Encoding: base64
  
          /9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a
          HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy
          MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAABAAEDASIA
          AhEBAxEB/8QAFQABAQAAAAAAAAAAAAAAAAAAAAf/xAAUEAEAAAAAAAAAAAAAAAAAAAAA/8QAFAEB
          AAAAAAAAAAAAAAAAAAAAAP/EABQRAQAAAAAAAAAAAAAAAAAAAAD/2gAMAwEAAhEDEQA/AL+AD//Z
          -----BOUNDARY
  
  + Response 200 (application/json)
  
      This response is returned when question image was added.
      
      + Attributes (Flashcard)
      
  ### Add image as answer [POST /decks/{deckId}/flashcards{flashcardId}/answerImage]
  + Request (multipart/form-data; boundary=---BOUNDARY)
  
          -----BOUNDARY
          Content-Disposition: form-data; name="file"; filename="image.jpg"
          Content-Type: image/jpeg
          Content-Transfer-Encoding: base64
  
          /9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a
          HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy
          MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAABAAEDASIA
          AhEBAxEB/8QAFQABAQAAAAAAAAAAAAAAAAAAAAf/xAAUEAEAAAAAAAAAAAAAAAAAAAAA/8QAFAEB
          AAAAAAAAAAAAAAAAAAAAAP/EABQRAQAAAAAAAAAAAAAAAAAAAAD/2gAMAwEAAhEDEQA/AL+AD//Z
          -----BOUNDARY
  
  + Response 200 (application/json)
  
      This response is returned when answer image was added.
      
      + Attributes (Flashcard)
  
  
  # Group User
  
  ## Users [/users]
  