package com.vtence.molecule.http;

public final class HeaderNames {
    public static final String ACCEPT_ENCODING = "Accept-Encoding";
    public static final String ACCEPT_LANGUAGE = "Accept-Language";
    public static final String ALLOW = "Allow";
    public static final String CACHE_CONTROL = "Cache-Control";
    public static final String CONTENT_ENCODING = "Content-Encoding";
    public static final String CONTENT_LANGUAGE = "Content-Language";
    public static final String CONTENT_LENGTH = "Content-Length";
    public static final String CONTENT_TYPE = "Content-Type";
    public static final String DATE = "Date";
    public static final String ETAG = "ETag";
    public static final String IF_MODIFIED_SINCE = "If-Modified-Since";
    public static final String IF_NONE_MATCH = "If-None-Match";
    public static final String LAST_MODIFIED = "Last-Modified";
    public static final String LOCATION = "Location";
    public static final String SERVER = "Server";
    public static final String TRANSFER_ENCODING = "Transfer-Encoding";

    private HeaderNames() {}

    public final class Response {
    }
}

package com.vtence.molecule.http;

public interface HeaderNames {
    static final String ACCEPT_ENCODING = "Accept-Encoding";
    static final String ACCEPT_LANGUAGE = "Accept-Language";
    static final String ALLOW = "Allow";
    static final String CACHE_CONTROL = "Cache-Control";
    static final String CONTENT_ENCODING = "Content-Encoding";
    static final String CONTENT_LANGUAGE = "Content-Language";
    static final String CONTENT_LENGTH = "Content-Length";
    static final String CONTENT_TYPE = "Content-Type";
    static final String DATE = "Date";
    static final String ETAG = "ETag";
    static final String IF_MODIFIED_SINCE = "If-Modified-Since";
    static final String IF_NONE_MATCH = "If-None-Match";
    static final String LAST_MODIFIED = "Last-Modified";
    static final String LOCATION = "Location";
    static final String SERVER = "Server";
    static final String TRANSFER_ENCODING = "Transfer-Encoding";
}

Make header names an interface with constants
Make header names an interface with constants
