anchor.diff:  - replaces 0th item in `array` array with `10`
   
   ```yaml
  +- type: remove
  +  path: /array/0
  +```
  +
  +- requires `array` to exist and be an array
  +- removes 0th item in `array`
  +
  +```yaml
   - type: replace
     path: /array/-
     value: 10
  
positive.code: 
  - requires that `key2` and `nested` hashes exist
  - sets `super_nested` to `10`
  
  ```yaml
  - type: replace
  
negative.code: - sets `key` to `10`
  
  ```yaml
  - type: remove
    path: /key
  ```
  
  - removes `key`
  
  ```yaml
  - type: replace
    path: /key_not_there
    value: 10
  ```
  
  - errors because `key_not_there` is expected (does not have `?`)
  
  ```yaml
  - type: remove
    path: /key_not_there
  ```
  
  - again this errors because `key_not_there` is expected (does not have `?`)
  
  ```yaml
  - type: replace
  