Examine source code of tab-murderer

{
  "author": "sasa cocic-banjanac",
  "manifest_version": 2,
  "name": "tab-killer",
  "version": "0.1.0",
  "description": "discard all tabs except the active one",
  "permissions": [
    "*://*/*",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}