I keep getting a NPE exception using the method setRoot() even though my RelNode is not null. Does anyone have any idea about what could be the problem?
java.lang.NullPointerException > at > org.apache.calcite.plan.volcano.VolcanoPlanner.registerImpl(VolcanoPlanner.java:1654) > at > org.apache.calcite.plan.volcano.VolcanoPlanner.setRoot(VolcanoPlanner.java:296) > at optimizer.VolcanoTest.main(VolcanoTest.java:134) > Thank you.
