Suggestion: New Trap: Wall Type - Porticulum

Specifics:

TLDR:? Essentially this is just another wall Segment that would be invisible to the enemy until they come in range.


Type: Trap Wall - is hidden until activated, like bombs and traps already in game.
Activation: Activates when ground Enemy ONLY reaches proximity bubble. The range of activation would be equivalent to the Big Bombs in game - just like bombs work currently
What occurs: simple.. Once Barbarian, or the like, walks near it the porticulum drops shut, making it another wall segment.

The porticulum would become available at level TH 8.
The porticulum would be equivalent to 1 wall segment in size
The porticulum would have the exact same amounts of levels as ALL Current Wall Segments in game and would need to be upgraded at the same TH level, speed as current TH level, speed of normal wall progression.
Costing Prices of upgrades: Equivalent to 1.5x the cost of the same level normal wall segment.
Porticulums have exact same health as walls of the same level.