# File lib/rubygems/package.rb, line 799 def self.open_from_io(io, mode = "r", signer = nil, &block) raise "Block needed" unless block_given? case mode when "r" security_policy = signer TarInput.open_from_io(io, security_policy, &block) when "w" TarOutput.open_from_io(io, signer, &block) else raise "Unknown Package open mode" end end