Convert a tree path to an iterator
| return | description | 
| true | A valid iterator for the input path | 
| false | Path does not reference a valid node | 
| false | Logic error | 
| iter | 
                 The iterator corresponding to the tree path  | 
            
| path | 
                 The path to convert to an iterator  | 
            
| 
                 True when iter represents a valid iterator  |