code: @Override
      public ListExecutionsResult listExecutions(ListExecutionsRequest request) {
          request = beforeClientExecution(request);
          return executeListExecutions(request);
      }
docs: <p>
  Lists the executions of a state machine that meet the filtering criteria. Results are sorted by time, with the
  most recent execution first.
  </p>
  <p>
  If <code>nextToken</code> is returned, there are more results available. The value of <code>nextToken</code> is a
  unique pagination token for each page. Make the call again using the returned token to retrieve the next page.
  Keep all other arguments unchanged. Each pagination token expires after 24 hours. Using an expired pagination
  token will return an <i>HTTP 400 InvalidToken</i> error.
  </p>
  <note>
  <p>
  This operation is eventually consistent. The results are best effort and may not reflect very recent updates and
  changes.
  </p>
  </note>
  
  @param listExecutionsRequest
  @return Result of the ListExecutions operation returned by the service.
  @throws InvalidArnException
  The provided Amazon Resource Name (ARN) is invalid.
  @throws InvalidTokenException
  The provided token is invalid.
  @throws StateMachineDoesNotExistException
  The specified state machine does not exist.
  @sample AWSStepFunctions.ListExecutions
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/states-2016-11-23/ListExecutions" target="_top">AWS API
  Documentation</a>