class Bundler::Installer

def resolve_if_needed(options)

returns whether or not a re-resolve was needed 
def resolve_if_needed(options)
  @definition.resolution_mode = options
  if !@definition.unlocking? && !options["force"] && !Bundler.settings[:inline] && Bundler.default_lockfile.file?
    return false if @definition.nothing_changed? && !@definition.missing_specs?
  end
  @definition.setup_sources_for_resolve
  true
end