lntest: add SuspendNode

lntest/harness.go

@@ -556,6 +556,20 @@ func (n *NetworkHarness) RestartNode(node *HarnessNode, callback func() error) e
 	return node.start(n.lndErrorChan)
 }
 
+// SuspendNode stops the given node and returns a callback that can be used to
+// start it again.
+func (n *NetworkHarness) SuspendNode(node *HarnessNode) (func() error, error) {
+	if err := node.stop(); err != nil {
+		return nil, err
+	}
+
+	restart := func() error {
+		return node.start(n.lndErrorChan)
+	}
+
+	return restart, nil
+}
+
 // ShutdownNode stops an active lnd process and returns when the process has
 // exited and any temporary directories have been cleaned up.
 func (n *NetworkHarness) ShutdownNode(node *HarnessNode) error {