This method allows filtering the stream. For each chunk in the stream the fn function will be called and if it returns a truthy value, the chunk will be passed to the result stream. If the fn function returns a promise - that promise will be awaited.
method
crypto.CipherChaCha20Poly1305.filter
@param fn
a function to filter chunks from the stream. Async or not.
@returns
a stream filtered with the predicate fn.