Allowing to easily determine if a header is actually present in the HTTP
connection. This is useful to determine if when using best_of the fallback
should be a global fallback for the header or whatever is returned by
best_of.
This avoids relying on the ordering of options passed to best_of, as without a
presence check the selected option would be the first option passed.
Allowing to easily determine if a header is actually present in the HTTP connection. This is useful to determine if when using
best_ofthe fallback should be a global fallback for the header or whatever is returned bybest_of.This avoids relying on the ordering of options passed to
best_of, as without a presence check the selected option would be the first option passed.