The BestSet chooses the best available method to query a remote index.

It combines IndexSet and APISet

Methods
N
Class Public methods
new(sources = Gem.sources)

Creates a BestSet for the given sources or Gem.sources if none are specified. sources must be a Gem::SourceList.

Source: show 

# File lib/rubygems/resolver/best_set.rb, line 12
def initialize sources = Gem.sources
  super()

  @sources = sources
end