code: public boolean catchReturn(Context ctxt)
  	{
  		ThreadState state = ctxt.threadState;
  		return state.stepline != null && state.nextctxt == null && state.outctxt == null;
  	}
docs: Test for whether an apply expression or operation call ought to catch a breakpoint
  after the return from the call. This only happens if we step into the call, so that
  when we step out it is clear where we're unwinding too, rather than jumping down
  the stack some considerable distance.
  
  @param ctxt
  @return