function findUntil(direction, rootNode, predicateFn, node) {
		while ((node = CaretUtils.findNode(node, direction, CaretCandidate.isEditableCaretCandidate, rootNode))) {
			if (predicateFn(node)) {
				return;
			}
		}
	}
This module lets you walk the document line by line
returing nodes and client rects for each line.

@private
@class tinymce.caret.LineWalker