code: func NestedFieldNoCopy(obj map[string]interface{}, fields ...string) (interface{}, bool, error) {
  	var val interface{} = obj
  
  	for i, field := range fields {
  		if val == nil {
  			return nil, false, nil
  		}
  		if m, ok := val.(map[string]interface{}); ok {
  			val, ok = m[field]
  			if !ok {
  				return nil, false, nil
  			}
  		} else {
  			return nil, false, fmt.Errorf("%v accessor error: %v is of the type %T, expected map[string]interface{}", jsonPath(fields[:i+1]), val, val)
  		}
  	}
  	return val, true, nil
  }
docs: // NestedFieldNoCopy returns a reference to a nested field.
  // Returns false if value is not found and an error if unable
  // to traverse obj.