The array function indexOf() was added to the ECMA-262 standard in the 5th edition; as such it may not be present in all browsers,eg. IE8.
In getRequest() ,customDimensionIdsAlreadyHandled is a array
we already have a polyfill function
indexOfArray included, so guess we just need to use it everywhere...
that's great,but you don't use it in customDimensionIdsAlreadyHandled