code: private int getNumRepeats(int level) {
  		int size = 1;
  		// Return 1 for illegally high level
  		if(level < getNumLevels()) {
  			for(Axis axis : axes.subList(level, getNumLevels())) {
  				size *= axis.getOrder();
  			}
  		}
  		return size;
  	}
docs: Get the number of leaves from a node at the specified level. This is
  equal to the product of all degrees at or below the level.
  @param level level of the tree to cut at
  @return Number of repeats (leaves of the tree).