Gateway Construction tech

I don't know if it's listed in the .txt, but Gateway Construction technology requires Mega-Engineering researched in order to appear as possible research - like it had 0x weight modifier unless Mega-Engineering has already been researched.

I found it out empirically, so it probably needs confirmation. Had Gateway Activation researched, Gateway in owned system and particle expert in physics research. And I researched one tech, then another, and another... and so on (that would be like 20 researched techs since I met all the prerequisites that are mentioned in the tree) and it did not appear for me to research. However, as soon as I researched Mega-Engineering, it appeared immediately after I finished next physics research. This would also be supported by the fact that Gateways are listed as Megastructures.