SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function arrayElement (children 1)
     ExpressionList (children 2)
      Identifier map
      Identifier key
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Function materialize (alias key) (children 1)
            ExpressionList (children 1)
             Literal \'key\'
           Function CAST (alias map) (children 1)
            ExpressionList (children 2)
             Function tuple (children 1)
              ExpressionList (children 2)
               Literal Array_[\'key\']
               Literal Array_[\'value\']
             Literal \'Map(String, String)\'
