default Resource generate(String requestId, String eTag, byte[] content, int off, int len) throws ResourceIOException {
        return generate(requestId, content, off, len);
    }
Creates a {@link Resource} from a given response body.
@param requestId a unique identifier for this particular response body.
@param eTag eTag Strong (unique) identifier for the resource entity
            with the given requestId, or {@code null} when not given
            or is weak (non-unique).
@param content byte array that represents the origin HTTP response body.
@param off   the start offset in the array.
@param len   the number of bytes to read from the array.
@return a {@code Resource} containing however much of
  the response body was successfully read.
@throws ResourceIOException
httpclient5-cache/src/main/java/org/apache/hc/client5/http/cache/ResourceFactory.java