Prepares a tree for imaging at many cells: the tree is rebuilt once, and each call images it at one cell. What a writer uses for the members of a block that share one formula.
Optional
When the printer is not loaded: a tree comes from parse, so load has resolved before there is one to image.
Prepares a tree for imaging at many cells: the tree is rebuilt once, and each call images it at one cell. What a writer uses for the members of a block that share one formula.