Inject into "obj" at index "index" as much as "length" from "data",
If length=1 you should concider inject(T[] obj, int index, T data),instead
Note all elements must be of the same class
Be aware that beside for index, the method doesn't check for valid arguments
inject "data" into "obj" at index "index"
Similar to others inject method, this one is optimized for injection of a single element
Note all elements must be of the same class