This seems like it should be a simple operation, but I must be completely blind because I can't find anything about it in the API docs at http://www.drupalcontrib.org/api/drupal/contributions!og!og.module/7.
I have a $gid. I need to check if it really is the gid of a valid group, and have access to the group information if it is.
I did find an old post somewhere saying to use og_load(), but that is out of date -- that function does not exist in the current API. Nor can I find a function with similar functionality.
There has to be a simple way to do this; it's hardly an outlier use-case. What am I missing?