Modifying certain public member functions

[xiongtx]

The instructions say not to modify any public interface:

You may add functions to your implementation as long as you keep all our original public interfaces intact for testing purposes.

But the description for b_plus_tree_internal_page.cpp suggests that we should set the page_id, parent_page_id, etc. in B_PLUS_TREE_INTERNAL_PAGE_TYPE::Init, even though it only takes max_size as a parameter. It seems that it originally did take more parameters, but this was later changed.

I find no references to Init in the local tests. Are we free to change this signature to pass page_id, etc.?