SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 3)
    Identifier x
    Identifier y
    Function arrayJoin (alias z) (children 1)
     ExpressionList (children 1)
      Literal Array_[\'a\', NULL, \'b\']
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.one
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 2)
       Literal Array_[UInt64_1, NULL, UInt64_3] (alias x)
       Function array (alias y) (children 1)
        ExpressionList (children 3)
         Literal Tuple_(NULL, \'\')
         Literal Tuple_(UInt64_123, \'Hello\')
         Literal Tuple_(UInt64_456, NULL)
   ExpressionList (children 3)
    OrderByElement (children 1)
     Identifier x
    OrderByElement (children 1)
     Identifier y
    OrderByElement (children 1)
     Identifier z
