SelectWithUnionQuery (children 2)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function count (children 1)
     ExpressionList (children 1)
      Function extractAllGroupsHorizontal (children 1)
       ExpressionList (children 2)
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal \'a\'
        Literal \'(a)\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function numbers (children 1)
       ExpressionList (children 1)
        Literal UInt64_1000000
 Identifier Null
