Add function to group object to send a value only if it was changed. #407

	name: PlatformIO CI

	on: [push, pull_request]

	jobs:
	build:

	runs-on: ubuntu-latest
	# strategy:
	# matrix:
	# example: [path/to/test/file.c, examples/file.ino, path/to/test/directory]

	steps:
	- uses: actions/checkout@v1
	- name: Set up Python
	uses: actions/setup-python@v1
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install platformio
	- name: Build knx-usb
	run: platformio ci --lib="." --project-conf=examples/knx-usb/platformio-ci.ini examples/knx-usb/src/main.cpp
	- name: Build knx-demo
	run: platformio ci --lib="." --project-conf=examples/knx-demo/platformio-ci.ini examples/knx-demo/knx-demo.ino
	- name: Build knx-demo-coupler
	run: platformio ci --lib="." --project-conf=examples/knx-demo-coupler/platformio-ci.ini examples/knx-demo-coupler/knx-demo-coupler.ino
	# - name: Run PlatformIO
	# run: pio ci --board=<ID_1> --board=<ID_2> --board=<ID_N>
	# env:
	# PLATFORMIO_CI_SRC: ${{ matrix.example }}

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