Trigger trigger = event.createTrigger();
// trigger.setMath(ASTNode.geq(new ASTNode(ASTNode.Type.NAME_TIME),
// new ASTNode(10)));
trigger.setMath(ASTNode.parseFormula("time >= 10"));
EventAssignment assignment1 = event.createEventAssignment();
assignment1.setVariable(k1);
assignment1.setMath(new ASTNode(34));
EventAssignment assignment2 = event.createEventAssignment();
assignment2.setVariable(k2);
assignment2.setMath(new ASTNode(k1));
new SBMLWriter().write(doc, System.out);
}