old_contents: const assert = require('assert')
  const Coordinate = require('../lib/coordinate')
  
  describe('Coordinate', () => {
  
    it("should calculate the distance from itself", () => {
      const a = new Coordinate(0, 0)
      assert.equal(a.distanceFrom(a), 0)
    })
  
    it("should calculate the distance from another coordinate along X axis", ()=>{
      const a = new Coordinate(0, 0)
      const b = new Coordinate(600, 0)
  
      assert.equal(a.distanceFrom(b), 600)
    })
  
    // it("should calculate the distance from another coordinate", ()=>{
    //   const a = new Coordinate(0, 0)
    //   const b = new Coordinate(300, 400)
    //
    //   assert.equal(a.distanceFrom(b), 500)
    // })
  })
  
new_contents: const assert = require('assert')
  const Coordinate = require('../lib/coordinate')
  
  describe('Coordinate', () => {
  
    it("should calculate the distance from itself", () => {
      const a = new Coordinate(0, 0)
      assert.strictEqual(a.distanceFrom(a), 0)
    })
  
    it("should calculate the distance from another coordinate along X axis", ()=>{
      const a = new Coordinate(0, 0)
      const b = new Coordinate(600, 0)
  
      assert.strictEqual(a.distanceFrom(b), 600)
    })
  
    // it("should calculate the distance from another coordinate", ()=>{
    //   const a = new Coordinate(0, 0)
    //   const b = new Coordinate(300, 400)
    //
    //   assert.strictEqual(a.distanceFrom(b), 500)
    // })
  })
  
subject: Replace deprecated assert.equals