default HttpHeadersBuilder set(Map<? extends CharSequence, String> entries) {
        requireNonNull(entries, "entries");
        return set(entries.entrySet());
    }
Retains all current headers but calls {@link #set(CharSequence, String)} for each header in
the specified {@code entries}.

@param entries the headers used to set the header values
@return {@code this}
core/src/main/java/com/linecorp/armeria/common/HttpHeadersBuilder.java