    # File lib/fog/terremark/shared.rb, line 223
          def check_shared_options(options)
            %w{ecloud vcloud}.each do |cloud|
              cloud_option_keys = options.keys.select { |key| key.to_s =~ /^terremark_#{cloud}_.*/ }
              unless cloud_option_keys.length == 0 || cloud_option_keys.length == 2
                raise ArgumentError.new("terremark_#{cloud}_username and terremark_#{cloud}_password required to access teremark")
              end
            end
          end