Inconsistent to_json() return type #1766

Initial Checks

• I have read and followed the docs and still think this is a bug

Description

to_json() returns a str for models inherited from BaseDoc, whereas it is bytes for DocList

Example Code

from docarray import BaseDoc, DocList


class MyModel(BaseDoc):
    text: str
        
print(type(MyModel(text="abc").to_json())) # <class 'str'>
print(type(DocList[MyModel]([MyModel(text="abc")]).to_json())) # <class 'bytes'>

Docarray Version

0.37.1

Affected Components

• Vector Database / Index
• Representing
• Sending
• storing
• multi modal data type