src/vs/editor/common/cursor/oneCursor.ts/Cursor/_validatePositionWithCache
class Cursor:	private static _validatePositionWithCache(viewModel: ICursorSimpleModel, position: Position, cacheInput: Position, cacheOutput: Position): Position {
		if (position.equals(cacheInput)) {
			return cacheOutput;
		}
		return viewModel.normalizePosition(position, PositionAffinity.None);
	}