How to create breakpoints programmatically?

Hi, we are trying to create a java breakpoint programmatically in our plugin. One complicating factor is that the java class does not (and cannot) exist in the IntelliJ project. To get round that we create a scratch file using ScratchRootType.getInstance().createScratchFile and then FileDocumentManager.getInstance().getDocument(scratchFile).

The problem we have is that the breakpoint request never makes it over the JDWP connection. We are creating the breakpoint using

ApplicationManager.getApplication().invokeAndWait(() -> debuggerManager.getBreakpointManager().addLineBreakpoint(scratchDoc, lineNumber));

and then set the breakpoint request using

 debugProcess.getManagerThread().schedule(new DebuggerCommandImpl() {
    protected void action() {
        List<Breakpoint> breakpoints = debuggerManager.getBreakpointManager().getBreakpoints();
        for (Breakpoint b : breakpoints) {
            if (BOOKMARK_CLASSNAME.equals(b.getClassName())) {
                b.setSuspendPolicy(DebuggerSettings.SUSPEND_ALL);
                b.createRequest(debugProcess);
            }
        }
    }
});

One strange thing is that the first time through b.getClassName() returns null although later it returns the class name.

Suspect the problem may be that async stuff is happening.

Is this the right way to go about creating breakpoints programmatically?

Many thanks,

David