lib/model/vertex.rb
def in count=0, via:nil
      if count.zero?
        @bufferedin ||= nodes :in,  1, via: via
      else
        nodes :in, count, via: via   # not cached
      end
    end
# get Vertices through in by edges of type via
get Vertices through in by edges of type via
get Vertices through in by edges of type via
def in count=0, via:nil
      if count.zero?
        @bufferedin ||= nodes :in,  1, via: via
      else
        nodes :in, count, via: via   
      end
    end
def in count = 0 , via : nil if count . zero? @bufferedin ||= nodes :in , 1 , via : via else nodes :in , count , via : via end end
get Vertices through in by edges of type via
get Vertices through in by edges of type via
# not cached
count
via