Under the heading:
Wiring The led Component Instance to the gpioComponent Component Instance and Rate Group
It appears that rateGroup1.RateGroupMemberOut[4] is suggested linked to two different ports. rateGroup1.RateGroupMemberOut[4] is already linked at the point where the following code is suggested inserted:
# Named connection group
connections LedBlinker {
# Rate Group 1 (1Hz cycle) ouput is connected to led's run input
rateGroup1.RateGroupMemberOut[4] -> led.run
# led's gpioSet output is connected to gpioDriver's gpioWrite input
led.gpioSet -> gpioDriver.gpioWrite
}