def insert(range, marker)
ranges[marker] = range
first_node = insert_node(range.first)
first_node.endpoint_of.push(marker)
last_node = insert_node(range.last)
last_node.endpoint_of.push(marker)
cur_node = first_node
cur_level = first_node.top_level
while next_node_at_level_inside_range?(cur_node, cur_level, range)
while can_ascend_from?(cur_node, cur_level) && next_node_at_level_inside_range?(cur_node, cur_level + 1, range)
cur_level += 1
end
cur_node = mark_forward_path_at_level(cur_node, cur_level, marker)
end
while node_inside_range?(cur_node, range)
while can_descend_from?(cur_level) && next_node_at_level_outside_range?(cur_node, cur_level, range)
cur_level -= 1
end
cur_node = mark_forward_path_at_level(cur_node, cur_level, marker)
end
end