Avro, heh. 1. avro schemas are defined in JSON 2. there is no way to define a map<string,string> with null values, this does not work: [{"type":"map","values"

Avro, heh. 1. avro schemas are defined in JSON 2. there is no way to define a map<string,string> with null values, this does not work: [{"type":"map","values":["string","null"]},"null"]