code: func (v *Object) GetNumber(keys ...string) (json.Number, error) {
  	child, err := v.getPath(keys)
  
  	if err != nil {
  		return "", err
  	}
  	n, err := child.Number()
  
  	if err != nil {
  		return "", err
  	}
  	return n, nil
  }
docs: // Gets the value at key path and attempts to typecast the value into a number.
  // Returns error if the value is not a json number.
  // Example:
  //		n, err := GetNumber("address", "street_number")