• Package Name: azure-storage-blob
• Package Version: 12.4.0b1
• Operating System: Win 10
• Python Version: 3.7.7

Describe the bug
A clear and concise description of what the bug is.

Request will be failed with additional property requires_sync when kwargs['requires_sync']=None

Recommended silution:

        if 'requires_sync' in kwargs:
            requires_sync = kwargs.pop('requires_sync')
            if requires_sync:
                headers['x-ms-requires-sync'] = str(requires_sync)

To Reproduce
Steps to reproduce the behavior:
1.

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
Add any other context about the problem here.