@FormatMethod
    static HttpData of(Charset charset, @FormatString String format, Object... args) {
        requireNonNull(charset, "charset");
        requireNonNull(format, "format");
        requireNonNull(args, "args");

        if (format.isEmpty()) {
            return empty();
        }

        return wrap(String.format(Locale.ENGLISH, format, args).getBytes(charset));
    }
Converts the specified formatted string into an {@link HttpData}. The string is formatted by
{@link String#format(Locale, String, Object...)} with {@linkplain Locale#ENGLISH English locale}.

@param charset the {@link Charset} to use for encoding string
@param format {@linkplain Formatter the format string} of the response content
@param args the arguments referenced by the format specifiers in the format string

@return a new {@link HttpData}. {@link #empty()} if {@code format} is empty.
core/src/main/java/com/linecorp/armeria/common/HttpData.java