SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.one
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 1)
       Function arrayFilter (alias arr_x) (children 1)
        ExpressionList (children 2)
         Function lambda (children 1)
          ExpressionList (children 2)
           Function tuple (children 1)
            ExpressionList (children 1)
             Identifier a
           Function in (children 1)
            ExpressionList (children 2)
             Function tuple (children 1)
              ExpressionList (children 2)
               Identifier a
               Function arrayJoin (children 1)
                ExpressionList (children 1)
                 Function array (children 1)
                  ExpressionList
             Literal NULL
         Function array (children 1)
          ExpressionList