docs: function get(path, defaultValue, opts) {
    let obj;
    const args = [].slice.call(arguments);
    path = args.shift();
    if (typeof args[args.length - 1] === 'object') {
      opts = args.pop();
    } else {
      opts = {};
    }
    defaultValue = args.pop();
  
    keys(path, opts)
      .sort((a, b) => a.length - b.length)
      .forEach(key => {
        let dotp = toDot(key, opts);
        if (!opts.caseSensitive) {
          dotp = dotp.toLowerCase();
        }
        const val = parse(process.env[key], opts);
        if (dotp === '') {
          obj = val;
        } else {
          if (typeof obj !== 'object') {
            obj = {};
          }
          dotProp.set(obj, dotp, val);
        }
      });
  
    let prefix = path;
    if (!opts.caseSensitive) {
      prefix = prefix.toLowerCase();
    }
    if (path === '') {
      return obj;
    }
    return dotProp.get(obj, prefix, defaultValue);
  }