Describe the bug
It's an invalid check null with SEC_WEB_SOCKET_KEY in Draft_6455.postProcessHandshakeResponseAsServer(request, response), maybe we can change to check the blank .
To Reproduce
If the field of SEC_WEB_SOCKET_KEY was null, it returned the blank.

It's only an null check with SEC_WEB_SOCKET_KEY, but the return value is a blank:

Maybe we need to add the blank checking:

Describe the bug


It's an invalid check null with SEC_WEB_SOCKET_KEY in Draft_6455.postProcessHandshakeResponseAsServer(request, response), maybe we can change to check the blank .
To Reproduce
If the field of SEC_WEB_SOCKET_KEY was null, it returned the blank.
It's only an null check with SEC_WEB_SOCKET_KEY, but the return value is a blank:
Maybe we need to add the blank checking:
