SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function concat (alias key1) (children 1)
     ExpressionList (children 3)
      Function currentDatabase (children 1)
       ExpressionList
      Literal \'_test1_\'
      Function modulo (children 1)
       ExpressionList (children 2)
        Identifier number
        Literal UInt64_3
    Function concat (alias key2) (children 1)
     ExpressionList (children 3)
      Function currentDatabase (children 1)
       ExpressionList
      Literal \'_test2_\'
      Function intDiv (children 1)
       ExpressionList (children 2)
        Identifier number
        Literal UInt64_3
   ExpressionList (children 3)
    Identifier number
    Function generateSerialID (children 1)
     ExpressionList (children 1)
      Identifier key1
    Function generateSerialID (children 1)
     ExpressionList (children 1)
      Identifier key2
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function numbers (children 1)
       ExpressionList (children 1)
        Literal UInt64_10
