SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function countIf (children 1)
     ExpressionList (children 2)
      Identifier number
      Function in (children 1)
       ExpressionList (children 2)
        Function toNullable (children 1)
         ExpressionList (children 1)
          Literal \'a\'
        Literal Tuple_(\'a\', \'b\')
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function numbers (children 1)
       ExpressionList (children 1)
        Literal UInt64_100