* type, classifier.
* This also means that none of those fields may be null. however, that doesn't eliminate the
* ability to have an empty string in place of a null.
*/
ArtifactResultsKey key = new ArtifactResultsKey();
key.groupId = StringUtils.defaultString( artifact.getGroupId() );
key.artifactId = StringUtils.defaultString( artifact.getArtifactId() );
key.version = StringUtils.defaultString( artifact.getVersion() );
key.artifactType = StringUtils.defaultString( artifact.getType() );
key.classifier = StringUtils.defaultString( artifact.getClassifier() );