SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function max (children 1)
     ExpressionList (children 1)
      Identifier x1
    Identifier x2
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test
   ExpressionList (children 2)
    Literal UInt64_1
    Literal UInt64_2