SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function countSubstrings (children 1)
     ExpressionList (children 2)
      Function toString (children 1)
       ExpressionList (children 1)
        Identifier number
      Literal \'\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Function numbers (children 1)
       ExpressionList (children 1)
        Literal UInt64_1