code: public static TraceComponent register(String name, Class<?> aClass, String[] groups) {
          return register(name, aClass, groups, null);
      }
docs: Register the provided name with the trace service and assign it to the
  provided groups.
  
  @param name
  a <code>String</code> to register a component for with
  the trace manager. The name is used in the registration
  process.
  @param aClass
  a valid <code>Class</code> to register a component for with
  the trace manager. The class is used for location of
  resource bundles.
  @param groups
  a list of the groups that the named component is a member of.
  Null is allowed. If null is passed, the name is not added to a
  group. Once added to a group, there is no corresponding
  mechanism to remove a component from a group.
  @return TraceComponent the <code>TraceComponent</code> corresponding to
  the name of the specified name.