LogicalRelation extends LogicalPlan { @Override public List<LogicalPlan> getChild() { return ImmutableList.of(); }  @Override List<LogicalPlan> getChild(); @Override R accept(LogicalPlanNodeVisitor<R, C> visitor, C context);  }
@Test public void logicalRelationHasNoInput() { LogicalPlan relation = LogicalPlanDSL.relation("index"); assertEquals(0, relation.getChild().size()); }