public Artifact(final String group,final String artifact,final String version){
  if (group == null || group.isEmpty())   throw new IllegalArgumentException("group cannot be null or empty");
  if (artifact == null || artifact.isEmpty())   throw new IllegalArgumentException("artifact cannot be null or empty");
  if (version == null || version.isEmpty())   throw new IllegalArgumentException("version cannot be null or empty");
  this.group=group;
  this.artifact=artifact;
  this.version=version;
}

public Artifact ( final String group , final String artifact , final String version ) { if ( group == null || group . isEmpty ( ) ) throw new IllegalArgumentException ( "group cannot be null or empty" ) ; if ( artifact == null || artifact . isEmpty ( ) ) throw new IllegalArgumentException ( "artifact cannot be null or empty" ) ; if ( version == null || version . isEmpty ( ) ) throw new IllegalArgumentException ( "version cannot be null or empty" ) ; this . group = group ; this . artifact = artifact ; this . version = version ; }
create a new instance .
