+property :runtime_directory, String
+property :runtime_directory_mode, Fixnum
+property :standard_input, String,
+ :is => %w(null tty tty-force tty-fail socket)
+property :standard_output, String,
+ :is => %w(inherit null tty journal syslog kmsg journal+console syslog+console kmsg+console socket)
+property :standard_error, String,
+ :is => %w(inherit null tty journal syslog kmsg journal+console syslog+console kmsg+console socket)