message: Use strict type checking.
diff: {
  "compilerOptions": {
  + // Targeted standard
  "target": "es6",
  "lib": [
  "es2017",
  "esnext.asynciterable"
  ],
  + // Module system
  "module": "commonjs",
  "moduleResolution": "node",
  - "isolatedModules": false,
  - "declaration": false,
  - "strictNullChecks": true,
  - "noImplicitAny": true,
  + // Strictness
  + "strict": true,
  "noUnusedLocals": true,
  "noUnusedParameters": true,
  + "skipLibCheck": true,
  + // Output
  + "sourceMap": true,
  "removeComments": false,
  "preserveConstEnums": true,
  - "suppressImplicitAnyIndexErrors": false,
  + "declaration": false,
  "outDir": "lib",
  - "rootDir": "src",
  - "sourceMap": true,
  - "skipLibCheck": true
  + "rootDir": "src"
  },
  "include": [
  "custom_typings/**/*.ts",
  