code: func (s *FixedSchema) Validate(v reflect.Value) bool {
  	v = dereference(v)
  
  	return (v.Kind() == reflect.Array || v.Kind() == reflect.Slice) && v.Type().Elem().Kind() == reflect.Uint8 && v.Len() == s.Size
  }
docs: // Validate checks whether the given value is writeable to this schema.