Prints cascade summary information to the screen
(if quiet = FALSE). '# cascades' is the number of cascades in
the object, '# nodes' is the number of nodes in the system (nodes
that can theoretically experience an event), '# nodes in cascades' is
the number of unique nodes of the system that experienced an event and
'# possible edges' is the number of edges that are possible given
the cascade data (see count_possible_edges for details.).
Additional summaries for each cascade are returned invisibly.
cascade), length (length of the cascade as an integer of how many
nodes experienced and event) and n_ties (number of tied event
times per cascade).