public String getNameWithoutTag(String optionalRegistry) {
        StringBuilder ret = new StringBuilder();
        if (registry != null || optionalRegistry != null) {
            ret.append(registry != null ? registry : optionalRegistry).append("/");
        }
        ret.append(repository);
        return ret.toString();
    }
Get the full name of this image like {@link #getNameWithoutTag()} does, but allow
an optional registry. This registry is used when this image does not already
contain a registry.

@param optionalRegistry optional registry to use when this image does not provide
                        a registry. Can be null in which case no optional registry is used*
@return full name with original registry (if set) or optional registry (if not <code>null</code>)
src/main/java/io/fabric8/maven/docker/util/ImageName.java