Is map schema's key an UTF8 or String type?

[Weishung Chung]

Hello Avro user,

I defined a map type in the schema with values of type double.
After reading the map from the schema, I realized that the key is of type
avro utils.utf8 and cannot be cast to java.lang.String

So, the following is not working when trying to loop through the entries of
the map.

for(Entry<String, Double> entry: map.entrySet())

Am I missing something ?

Thank you so much,