test: improve test coverage of `BTreeMap::Node` #335

	name: CI
	on: [pull_request]

	jobs:
	build:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	rust: [ 1.67.0 ]

	steps:
	- uses: actions/checkout@v2

	- name: Cache Cargo
	uses: actions/cache@v2
	with:
	path: \|
	~/.cargo/registry
	~/.cargo/git
	target
	key: ${{ matrix.build }}-cargo-${{ hashFiles('**/Cargo.lock') }}
	restore-keys: \|
	${{ matrix.build }}-cargo-

	- name: Install Rust
	run: \|
	rustup update ${{ matrix.rust }} --no-self-update
	rustup default ${{ matrix.rust }}
	rustup component add rustfmt
	rustup component add clippy

	- name: Check Format
	run: cargo fmt --all -- --check

	- name: Clippy
	run: cargo clippy --tests --benches -- -D clippy::all

	- name: Test
	run: cargo test
	env:
	RUST_BACKTRACE: 1

	examples:
	runs-on: ubuntu-20.04

	steps:
	- uses: actions/checkout@v2
	- uses: actions/cache@v2
	with:
	path: \|
	~/.cargo/registry
	~/.cargo/git
	target
	key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}-1

	- name: Install Rust
	run: \|
	rustup update ${{ matrix.rust }} --no-self-update
	rustup default ${{ matrix.rust }}
	rustup target add wasm32-unknown-unknown

	- name: Install DFX
	run: \|
	wget --output-document install-dfx.sh "https://internetcomputer.org/install.sh"
	DFX_VERSION=${DFX_VERSION:=0.14.1} bash install-dfx.sh < <(yes Y)
	rm install-dfx.sh
	dfx cache install
	echo "$HOME/bin" >> $GITHUB_PATH

	- name: Run test
	run: \|
	bash examples/test.sh

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