code: @Override
      public GetCallerIdentityResult getCallerIdentity(GetCallerIdentityRequest request) {
          request = beforeClientExecution(request);
          return executeGetCallerIdentity(request);
      }
docs: <p>
  Returns details about the IAM identity whose credentials are used to call the API.
  </p>
  
  @param getCallerIdentityRequest
  @return Result of the GetCallerIdentity operation returned by the service.
  @sample AWSSecurityTokenService.GetCallerIdentity
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/sts-2011-06-15/GetCallerIdentity" target="_top">AWS API
  Documentation</a>