Those arrays are used as "execution plan" in order to only execute non-trivial transformations\preparations for every integer i array(i) contains first non trivial transformation\preparation on particular tree subtype.
Those arrays are used as "execution plan" in order to only execute non-trivial transformations\preparations for every integer i array(i) contains first non trivial transformation\preparation on particular tree subtype. If no nontrivial transformation are left stored value is greater than transformers.size
This class maintains track of which methods are redefined in MiniPhases and creates execution plans for transformXXX and prepareXXX Thanks to Martin for this idea
NXTransformations.index for format of plan