code: func StrictDecode(target interface{}) error {
  	nFields, err := decode(target, true)
  	if err != nil {
  		return err
  	}
  
  	// if we didn't do anything - the user probably did something
  	// wrong like leave all fields unexported.
  	if nFields == 0 {
  		return ErrInvalidTarget
  	}
  
  	return nil
  }
docs: // StrictDecode is similar to Decode except all fields will have an implicit
  // ",strict" on all fields.