SelectWithUnionQuery (children 3)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier a
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t_max_rows_to_read
   Function or (children 1)
    ExpressionList (children 2)
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier a
       Literal UInt64_10
     Function equals (children 1)
      ExpressionList (children 2)
       Identifier a
       Literal UInt64_20
 Identifier Null
 Set
