anchor.diff:  
   ### <a id="environment-variable-npm-config-production"></a> NPM_CONFIG_PRODUCTION
   
  -Installs only production dependencies if NPM install is used.
  +The `NPM_CONFIG_LOGLEVEL` environment variable installs only production dependencies if NPM install is used.
   
   * Set by: `node-engine-cnb`
   * Phases: `build`
  
positive.code: 
  ### <a id="environment-variable-path"></a> PATH
  
  Appends the `node_modules/.bin` directory onto the `$PATH`.
  
  * Set by: `yarn-cnb`
  * Phases: `build`
  
negative.code: 
  The Node Engine CNB allows you to specify a version of Node.js to use during deployment. This version can be specified in a number of ways, including through `.nvmrc`, `buildpack.yml`, or `package.json` files. When specifying a version of the Node.js engine, you must choose a version that is available within the buildpack.
  
  When you specify a version, the buildpack prioritizes the versions specified in each possible configuration location with the following precedence, from highest to lowest: `buildpack.yml`, `package.json`, `.nvmrc`.
  
  ### <a id='buildpack-yml'></a> Using buildpack.yml
  
  