static RequestHeaders of(HttpMethod method, String path,
                             CharSequence name1, String value1,
                             CharSequence name2, String value2) {
        return builder(method, path).add(name1, value1)
                                    .add(name2, value2)
                                    .build();
    }
Returns a new {@link RequestHeaders} with the specified {@link HttpMethod}, {@code path} and
additional headers.
core/src/main/java/com/linecorp/armeria/common/RequestHeaders.java