group_by.cnss()

[maurolepore]

group_by.cns_lst() (cns_lst or censuses) stores metadata on variables to group by and adds the class grouped_cns_lst. This travels as in dplyr::group_by(), and is used in demography functions to internally create a column that creates a by column by uniting all the columns described by group_by().

This means that demography functions no longer need the by argument. It is used internally if the data is of class grp_cns_lst (or grouped_censuses_list).