code: private Artifact extractArtifact(Artifact a, String type, String classifier) {
  		if (a == null) {
  			return a;
  		}
  
  		Artifact result = new DefaultArtifact(a.getGroupId(),
  				                              a.getArtifactId(),
  				                              a.getVersionRange(),
  				                              a.getScope(),
  				                              type,
  				                              classifier,
  				                              new DefaultArtifactHandler(type));
  		
  		return result;
  	}
docs: This returns a {@link DefaultArtifact} object with the same groupId,
  artifactId, version and scope as the main artifact of the project
  (for instance 'bw-ear' or 'projlib').
  
  This {@link DefaultArtifact} will have its own {@link type} and
  {@link classifier}.
  
  @param a
  @param type
  @param classifier
  @return