12
13
"launchpad.net/juju-core/constraints"
13
14
"launchpad.net/juju-core/environs/imagemetadata"
14
15
"launchpad.net/juju-core/environs/instances"
15
16
"launchpad.net/juju-core/environs/simplestreams"
19
19
// preferredTypes is a list of machine types, in order of preference so that