class Pry::Pager

def best_available

avoided by using `.open` instead.
you must rescue `Pry::Pager::StopPaging`. These requirements can be
must call `#close` when you're done writing output to a pager, and
pagers accept output with `#puts`, `#print`, `#write`, and `#<<`. You
available, and `NullPager` if the user has disabled paging. All
`SystemPager` if possible, `SimplePager` if `SystemPager` isn't
Return an instance of the "best" available pager class -- 
def best_available
  if !pry_instance.config.pager
    NullPager.new(pry_instance.output)
  elsif !SystemPager.available? || Helpers::Platform.jruby?
    SimplePager.new(pry_instance.output)
  else
    SystemPager.new(pry_instance.output)
  end
end