Paweł Kozioł

Add missing import for SerializerError

1

### Description _What behavior does this PR change, and why?_ Fixes: ``` except SerializerError as e: ^^^^^^^^^^^^^^^ NameError: name 'SerializerError' is not defined ``` ### Author Validation _Describe the validation...

## The feature Ability to distinguish different environments by looking at the sidebar. Short string with configurable env name. Ideally via environment property. Example from Ververica:   Documentation: https://docs.ververica.com/vvp/platform-operations/themes...

Fix SchemaRegistryClient docs

5

Fixed few mismached URLs and missing default value for a parameter.