def check_shared_options(options)
%{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