Add has method #18

	name: CI
	on:
	push:
	branches: [ main ]
	pull_request:
	branches: [ main ]
	jobs:
	test:
	strategy:
	matrix:
	os: [ ubuntu-latest, macos-latest, windows-latest ]
	go: [ 1.16.x ]
	runs-on: ${{ matrix.os }}
	steps:
	- name: Checkout
	uses: actions/checkout@v2

	- name: Setup Go
	uses: actions/setup-go@v2
	with:
	go-version: ${{ matrix.go }}

	- name: Go Env
	run: \|
	go env

	- name: Test
	run: \|
	go test . -v -race -tags hashring_debug,hashring_trace

Provide feedback