public ContentTooLargeExceptionBuilder contentLength(HttpHeaders headers) {
        requireNonNull(headers, "headers");
        contentLength = headers.contentLength();
        return this;
    }
Sets the actual content length in bytes, as specified in the {@code content-length} header,
from the specified {@link HttpHeaders}. If the {@code content-length} header is missing or
its value is not valid, {@code -1} (unknown) will be set instead.
core/src/main/java/com/linecorp/armeria/common/ContentTooLargeExceptionBuilder.java