What does the methods operation do in a Pacemaker cluster resource?

Issue

• Some cluster resource agents offer a methods operation.
• The LVM resource agent has an operation called methods that is not found in most other resource agents.

  Resource: test_lvm (class=ocf provider=heartbeat type=LVM)
   Attributes: exclusive=true volgrpname=test_vg
   Operations: methods interval=0s timeout=5 (test_lvm-methods-interval-0s)
               monitor interval=120s timeout=180s (test_lvm-monitor-interval-120s)
               start interval=0s timeout=180s (test_lvm-start-interval-0s)
               stop interval=0s timeout=180s (test_lvm-stop-interval-0s)