SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function hostName (alias h) (children 1)
     ExpressionList
    Function count (children 1)
     ExpressionList
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function cluster (children 1)
       ExpressionList (children 2)
        Identifier test_cluster_two_shards
        Identifier system.one
   ExpressionList (children 1)
    Identifier h