SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Function overlay (children 1)
     ExpressionList (children 3)
      Literal \'\'
      Literal \'_\'
      Literal UInt64_6
    Function overlayUTF8 (children 1)
     ExpressionList (children 3)
      Literal \'\'
      Literal \'_\'
      Literal UInt64_6