code: private List<Mutation> executeInternal(ByteBuffer key, ColumnFamily columnFamily)
      {
          Map<String, TriggerDefinition> triggers = columnFamily.metadata().getTriggers();
          if (triggers.isEmpty())
              return null;
          List<Mutation> tmutations = Lists.newLinkedList();
          Thread.currentThread().setContextClassLoader(customClassLoader);
          try
          {
              for (TriggerDefinition td : triggers.values())
              {
                  ITrigger trigger = cachedTriggers.get(td.classOption);
                  if (trigger == null)
                  {
                      trigger = loadTriggerInstance(td.classOption);
                      cachedTriggers.put(td.classOption, trigger);
                  }
                  Collection<Mutation> temp = trigger.augment(key, columnFamily);
                  if (temp != null)
                      tmutations.addAll(temp);
              }
              return tmutations;
          }
          catch (Exception ex)
          {
              throw new RuntimeException(String.format("Exception while creating trigger on CF with ID: %s", columnFamily.id()), ex);
          }
          finally
          {
              Thread.currentThread().setContextClassLoader(parent);
          }
      }
docs: Switch class loader before using the triggers for the column family, if
  not loaded them with the custom class loader.