SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function arrayFirstIndex (children 1)
     ExpressionList (children 2)
      Function lambda (children 1)
       ExpressionList (children 2)
        Function tuple (children 1)
         ExpressionList (children 1)
          Identifier x
        Literal UInt64_1
      Function emptyArrayUInt8 (children 1)
       ExpressionList
