The attribute is both readable and writable, the reader implementation is just at https://github.com/limhoff-r7/metasploit-framework/blob/a587c04cc0d32bdcf88e684c0b9a252acf519ecc/app/models/metasploit/framework/attempt/creation/base.rb#L50-L55 since I needed to write it manually (instead of using `attr_reader` or `attr_accessor`) since I wanted to set a lazy evaluated default of `Time.now.utc`.