Constants
| CONTENT_ENCODING | = | "Content-Encoding" |
| CONTENT_SECURITY_POLICY | = | "Content-Security-Policy" |
| CONTENT_SECURITY_POLICY_REPORT_ONLY | = | "Content-Security-Policy-Report-Only" |
| FEATURE_POLICY | = | "Feature-Policy" |
| LOCATION | = | "Location" |
| SERVER_TIMING | = | "Server-Timing" |
| STRICT_TRANSPORT_SECURITY | = | "Strict-Transport-Security" |
| VARY | = | "Vary" |
| X_CASCADE | = | "X-Cascade" |
| X_REQUEST_ID | = | "X-Request-Id" |