Object.switchDirectionTime
Type: Number
Default value: 5000
Overview

Time, in milliseconds, after which an object changes its direction. (This property is needed, if
ai_type
in "guard" option)
Examples

Decrease the time, in milliseconds, after which an object changes its direction (i.e. look to the right side an then look to the left side)
local newAI = require('classes.SimpleAI').newAI
-- enemy instance
local enemy = newAI({group = mainGroup, img = "snailWalk1.png", x = halfW-50, y = display.contentHeight-500, ai_type = "guard"}) 
enemy.switchDirectionTime = 2000 -- the object will quicker change its direction