SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function dictGetOrDefault (children 1)
     ExpressionList (children 4)
      Literal \'flat_dictionary\'
      Literal \'array_value\'
      Function toUInt64 (children 1)
       ExpressionList (children 1)
        Literal UInt64_1
      Literal Array_[UInt64_2, UInt64_3, UInt64_4]
