Feature request: allow sampling snapshot recording from command line only in headless environment

Is your feature request related to a problem? Please describe.
I would like to be able to record snapshots of sampled CPU usage from the command line in a headless environment, and then later open that snapshot in the VisualVM GUI. The command line docs suggest that it's possible to start and stop sampling from a command line, but there doesn't seem to be a working option to dump that information to a snapshot file.

Describe the solution you'd like
New command line option to dump CPU (or memory) sampling results to a file that can be loaded in the GUI later

Describe alternatives you've considered
I have tried the following series of commands, hoping that it might work, but it doesn't seem to do anything:

[kmilner@e19-12 ~]$ mkdir /tmp/visualvm_temp/
[kmilner@e19-12 ~]$ ~/visualvm_21/bin/visualvm -J-Dvisualvm.tmpdir=/tmp/visualvm_temp/ --start-cpu-sampler 31650
/home1/kmilner/visualvm_21/platform/lib/nbexec: WARNING: environment variable DISPLAY is not set
^Z
[1]+  Stopped                 ~/visualvm_21/bin/visualvm -J-Dvisualvm.tmpdir=/tmp/visualvm_temp/ --start-cpu-sampler 31650
[kmilner@e19-12 ~]$ bg
[1]+ ~/visualvm_21/bin/visualvm -J-Dvisualvm.tmpdir=/tmp/visualvm_temp/ --start-cpu-sampler 31650 &
[kmilner@e19-12 ~]$ ~/visualvm_21/bin/visualvm -J-Dvisualvm.tmpdir=/tmp/visualvm_temp/ --snapshot-sampler 31650
/home1/kmilner/visualvm_21/platform/lib/nbexec: WARNING: environment variable DISPLAY is not set
[kmilner@e19-12 ~]$ ls /tmp/visualvm_temp/
[kmilner@e19-12 ~]$

Additional context
Add any other context or screenshots about the feature request here.

Start with the command-line options documented at the linked command line documentation, especially --start-cpu-sampler and --snapshot-sampler, and reproduce the headless commands shown in the issue. Trace how sampling is started and stopped without DISPLAY, then define a command-line path that writes CPU or memory results to a snapshot file loadable in the VisualVM GUI.