This function generates the well-studied "basic networks".
load_KEGG_refnet(organism = "hsa")
a NFPRefnet object
KEGG pathway is a well-studied and the most widely used biolocgial networks database. This function help users to load kegg pathway maps as the basic networks.
Appanrently, users can also load their customozied biological networks as the basic networks by creating a new NFPRefnet object.