code: func (v *Object) GetNullArray(keys ...string) (int64, error) {
  	child, err := v.getPath(keys)
  
  	if err != nil {
  		return 0, err
  	}
  	array, err := child.Array()
  
  	if err != nil {
  		return 0, err
  	}
  	var length int64 = 0
  
  	for _, arrayItem := range array {
  		err := arrayItem.Null()
  
  		if err != nil {
  			return 0, err
  		}
  		length++
  	}
  	return length, nil
  }
docs: // Gets the value at key path and attempts to typecast the value into an array of nulls.
  // Returns length, or an error if the value is not a json array or if any of the contained objects are not nulls.