devicegraph_query-1.rb

query = DevicegraphQuery.new(a_devicegraph)
fine_query = query.with_disk(name: ["/dev/sda", "/dev/sdb"])
more_fine_query = fine_query.with_partition(type: :primary)
part_query = query.with_partition(name: ["/dev/sda2", "/dev/sdc3"])

# All these calls return arrays
query.filesystems # all the file systems in the devicegraph
fine_query.filesystems # Filesystems in the chosen disks
more_fine_query.filesystems # fs in primary parts of chosen disks
part_query.filesystems # Filesystems in sda2 and sdc3