SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function arrayJoin (alias x) (children 1)
     ExpressionList (children 1)
      Literal Array_[Array_[Array_[UInt64_1], Array_[UInt64_2]], Array_[Array_[UInt64_1]]]
   Function equals (children 1)
    ExpressionList (children 2)
     Function length (children 1)
      ExpressionList (children 1)
       Identifier x
     Literal UInt64_2
