SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function arrayFirst (children 1)
     ExpressionList (children 2)
      Function lambda (children 1)
       ExpressionList (children 2)
        Function tuple (children 1)
         ExpressionList (children 1)
          Identifier x
        Literal \'string\'
      Literal Array_[UInt64_1, UInt64_2, UInt64_3]
