code: @Override
      public GetUsagePlanResult getUsagePlan(GetUsagePlanRequest request) {
          request = beforeClientExecution(request);
          return executeGetUsagePlan(request);
      }
docs: <p>
  Gets a usage plan of a given plan identifier.
  </p>
  
  @param getUsagePlanRequest
  The GET request to get a usage plan of a given plan identifier.
  @return Result of the GetUsagePlan operation returned by the service.
  @throws BadRequestException
  The submitted request is not valid, for example, the input is incomplete or incorrect. See the
  accompanying error message for details.
  @throws UnauthorizedException
  The request is denied because the caller has insufficient permissions.
  @throws NotFoundException
  The requested resource is not found. Make sure that the request URI is correct.
  @throws TooManyRequestsException
  The request has reached its throttling limit. Retry after the specified time period.
  @sample AmazonApiGateway.GetUsagePlan