SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier t.a
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 1)
       Identifier t.b
