Simplify `fetch()` and `fetch_items()` in the backends #476

	name: tests

	on:
	push:
	branches:
	- '**'
	tags:
	- '!**'
	pull_request:
	branches:
	- '**'

	jobs:
	tests:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version: ['3.8', '3.9', '3.10', '3.11']

	name: Python ${{ matrix.python-version }}
	steps:
	- uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d # v5.1.0
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install and set up Poetry
	run: \|
	curl -sSL https://install.python-poetry.org \| python3 -
	echo "PATH=$HOME/.poetry/bin:$PATH" >> $GITHUB_ENV
	- name: Install dependencies
	run: \|
	poetry install -vvv
	- name: Lint with flake8
	run: \|
	poetry run flake8
	- name: Tests and Coverage
	env:
	GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	run: \|
	cd tests
	poetry run coverage run --source=perceval run_tests.py
	- name: Coveralls
	uses: coverallsapp/github-action@643bc377ffa44ace6394b2b5d0d3950076de9f63 # v2.3.0
	with:
	coverage-reporter-version: "v0.6.9"
	flag-name: run ${{ join(matrix.*, ' - ') }}
	parallel: true

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