class ParallelInstaller

def enqueue_specs

are installed.
previously installed specifications. We continue until all specs
Later we call this lambda again to install specs that depended on
We enqueue all gem specs that do not have any dependencies.
Keys in the remains hash represent uninstalled gems specs. 
def enqueue_specs
  @specs.select(&:ready_to_enqueue?).each do |spec|
    if spec.dependencies_installed? @specs
      worker_pool.enq spec
      spec.state = :enqueued
    end
  end
end