An object that represents the action of adding a header to a request. This rule applies only to HTTP listeners.
If a matching header already exists in the request, the system removes all of its occurrences, and then adds the new header.
The system does not distinquish between underscore and dash characters in headers. That is, it treats `example_header_name` and `example-header-name` as identical. Oracle recommends that you do not rely on underscore or dash characters to uniquely distinguish header names.
A header name that conforms to RFC 7230.
A header value that conforms to RFC 7230.