code: public Task certMgrRefreshCACertificatesAndCRLs_Task(HostSystem[] hostSystems) throws RuntimeFault, SystemError, RemoteException {
          ManagedObjectReference taskMor = getVimService().certMgrRefreshCACertificatesAndCRLs_Task(getMOR(), MorUtil.createMORs(hostSystems));
          return new Task(getServerConnection(), taskMor);
      }
docs: Returns a Task you can use to track the status of the job that
  re-fetches certificates of trusted CAs and the Certificate
  Revocation Lists (CRL) from the appropriate authoritative
  source and pushes them to the hosts
  
  @param hostSystems an Array of HostSystem objects
  @return Task from vSphere
  @throws RuntimeFault    Thrown if any type of runtime fault is thrown that is not covered by the other faults; for example, a communication error.
  @throws SystemError     Thrown if any of the needed actions fails.
  @throws RemoteException
  @see com.vmware.vim25.mo.Task