code: def list_licenses(service_instance=None):
      '''
      Lists all licenses on a vCenter.
  
      service_instance
          Service instance (vim.ServiceInstance) of the vCenter/ESXi host.
          Default is None.
  
      .. code-block:: bash
  
          salt '*' vsphere.list_licenses
      '''
      log.trace('Retrieving all licenses')
      licenses = salt.utils.vmware.get_licenses(service_instance)
      ret_dict = [{'key': l.licenseKey,
                   'name': l.name,
                   'description': l.labels[0].value if l.labels else None,
                   # VMware handles unlimited capacity as 0
                   'capacity': l.total if l.total > 0 else sys.maxsize,
                   'used': l.used if l.used else 0}
                   for l in licenses]
      return ret_dicf list_licenses(service_instance=None):
      '''
      Lists all licenses on a vCenter.
  
      service_instance
          Service instance (vim.ServiceInstance) of the vCenter/ESXi host.
          Default is None.
  
      .. code-block:: bash
  
          salt '*' vsphere.list_licenses
      '''
      log.trace('Retrieving all licenses')
      licenses = salt.utils.vmware.get_licenses(service_instance)
      ret_dict = [{'key': l.licenseKey,
                   'name': l.name,
                   'description': l.labels[0].value if l.labels else None,
                   # VMware handles unlimited capacity as 0
                   'capacity': l.total if l.total > 0 else sys.maxsize,
                   'used': l.used if l.used else 0}
                   for l in licenses]
      return ret_dict
docs: Lists all licenses on a vCenter.
  
      service_instance
          Service instance (vim.ServiceInstance) of the vCenter/ESXi host.
          Default is None.
  
      .. code-block:: bash
  
          salt '*' vsphere.list_licenses