anchor.diff:  
   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.
  -
  -**(highest)** `buildpack.yml` > `package.json` > `.nvmrc` **(lowest)**
  +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
   
  
positive.code:   optimize-memory: true
  ```
  
  ### <a id="optimize-memory-env-var"></a> Using the OPTIMIZE_MEMORY Environment Variable
  
  To enable memory optimization through the `OPTIMIZE_MEMORY` environment variable, set it to `true`.
  
  
negative.code: 
  ### <a id="environment-variable-npm-config-loglevel"></a> NPM_CONFIG_LOGLEVEL
  
  The `NPM_CONFIG_LOGLEVEL` environment variable sets the level of logging NPM uses.
  
  * Set by: `node-engine-cnb`
  * Phases: `build`
  