SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 3)
    Identifier x
    Identifier a
    Identifier arr
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Function arrayJoin (alias x) (children 1)
            ExpressionList (children 1)
             Literal Array_[\'Hello\', \'Goodbye\']
           Literal Array_[UInt64_1, UInt64_2, UInt64_3] (alias arr)
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 1)
       Identifier arr (alias a)