code: public Breakpoint setTracepoint(PStm stmt, String trace) throws Exception
  	{
  		BreakpointManager.setBreakpoint(stmt, new Tracepoint(stmt.getLocation(), ++nextbreakpoint, trace));
  		breakpoints.put(nextbreakpoint, BreakpointManager.getBreakpoint(stmt));
  		return BreakpointManager.getBreakpoint(stmt);
  	}
docs: Set a statement tracepoint. A tracepoint does not stop execution, but evaluates and displays an expression before
  continuing.
  
  @param stmt
  The statement to trace.
  @param trace
  The expression to evaluate.
  @return The Breakpoint object created.
  @throws Exception
  Expression is not valid.