SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Identifier a
    Function count (children 1)
     ExpressionList (children 1)
      Identifier b
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier group_by_all
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier a