Improve getting process group leader

process/process_windows.go

@@ -1,4 +1,21 @@
 package process
 
+import (
+	"context"
+)
+
 // SystemProcessID is the PID of the System/Kernel itself.
 const SystemProcessID = 4
+
+// GetProcessGroupLeader returns the process that leads the process group.
+// Returns nil on Windows, as it does not have process groups.
+func (p *Process) FindProcessGroupLeader(ctx context.Context) error {
+	// TODO: Get "main" process of process job object.
+	return nil
+}
+
+// GetProcessGroupID returns the process group ID of the given PID.
+// Returns the undefined process ID on Windows, as it does not have process groups.
+func GetProcessGroupID(ctx context.Context, pid int) (int, error) {
+	return UndefinedProcessID, nil
+}