code: @Override
      public ListQualificationTypesResult listQualificationTypes(ListQualificationTypesRequest request) {
          request = beforeClientExecution(request);
          return executeListQualificationTypes(request);
      }
docs: <p>
  The <code>ListQualificationTypes</code> operation returns a list of Qualification types, filtered by an optional
  search term.
  </p>
  
  @param listQualificationTypesRequest
  @return Result of the ListQualificationTypes operation returned by the service.
  @throws ServiceException
  Amazon Mechanical Turk is temporarily unable to process your request. Try your call again.
  @throws RequestErrorException
  Your request is invalid.
  @sample AmazonMTurk.ListQualificationTypes
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/mturk-requester-2017-01-17/ListQualificationTypes"
  target="_top">AWS API Documentation</a>