Function ws_mask

ws_mask(
data: Uint8Array<ArrayBuffer>,
key: Uint8Array<ArrayBuffer>,
): Uint8Array<ArrayBuffer>
Applies or removes a WebSocket masking key. XOR is symmetric, so masking and unmasking use the same operation.
Parameters
- data: Uint8Array<ArrayBuffer>
  The data to mask/unmask.
- key: Uint8Array<ArrayBuffer>
  The 4-byte masking key.
Returns Uint8Array<ArrayBuffer>
The masked/unmasked data.