Hi folks, Recently I'm looking into the KeyValue schema and found **FOUR** static methods in `Schema` to create a `KeyValueSchema<K, V>` object:
1. KeyValue(Class<K> key, Class<V> value); 2. KeyValue(Class<K> key, Class<V> value, SchemaType type); 3. KeyValue(Schema<K> key, Schema<V> value); 4. KeyValue(Schema<K> key, Schema<V> value, KeyValueEncodingType keyValueEncodingType); IMO, having too many overloads is not user-friendly. I turned to the official website and found overload 4 is used. The overload 3 is just a simple version of overload 4 whose encoding type is `INLINE`, but it's not clear. I opened a PR https://github.com/apache/pulsar/pull/17256 to make it more clear. However, for overload 1 and 2, I can only find two references in unit tests `testAllowNullAvroSchemaCreate` and `testAllowNullJsonSchemaCreate`. From the very simple JavaDocs, it looks like they are only available for JSON and AVRO schemas. Then I found the original PR to introduce these overloads: https://github.com/apache/pulsar/pull/2885 Code has been changed a lot since that. It looks other codes are not much related to these two overloads now. IMO, we should not encourage users to use these two overloads, so I suggest marking them as deprecated and might remove them in future releases. Thanks, Yunze
