Create a class for the summary information of a data.frame.
Define it as an S4 class with slots for the following;
validation info
information about the df the summary was run on, to check against if an existing summary object is loaded for a df
variable summaries
a list with element for each variable summarised, each element is a list where each element is a data.frame containing the summaries for that variable grouped in a particular way
Create a class for the summary information of a data.frame. Define it as an S4 class with slots for the following;