InsertQuery   (children 3)
 Identifier merge
 ExpressionList (children 1)
  Identifier x
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Identifier number (alias x)
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier system.numbers
    Literal UInt64_10