0 if the two conditions contain the same number of HTTP request methods
Less than 0 if "this" instance has an HTTP request method but "other" doesn't
Greater than 0 "other" has an HTTP request method but "this" doesn't
Check if any of the HTTP request methods match the given request and
return an instance that contains the matching HTTP request method only.
exchange - the current exchange
the same instance if the condition is empty (unless the request
method is HTTP OPTIONS), a new condition with the matched request method,
or null if there is no match or the condition is empty and the
request method is OPTIONS.