code: function checkOpts(next) {
          /* failsafe */
          if (options === undefined) {
            _log('error', 'no options given to .compile()');
            process.exit();
          }
  
          /**
           * Have we been given a custom flag for python executable?
           **/
          if (
            options.python !== 'python' &&
            options.python !== '' &&
            options.python !== undefined
          ) {
            if (isWin) {
              isPy = options.python.replace(/\//gm, '\\'); // use windows file paths, batch is sensitive.
            } else {
              isPy = options.python;
            }
  
            _log('set python as ' + isPy);
          } else {
            isPy = 'python';
          }
  
          // remove dots
          options.framework = options.framework.replace(/\./g, '');
  
          // set outter-scope framework variable.
          framework = options.framework;
          _log('framework => ' + framework);
  
          version = options.nodeVersion; // better framework vc
  
          // check iojs version
          if (framework === 'iojs' && version === 'latest') {
            _log('fetching iojs versions');
            mkdirp(options.nodeTempDir); // make temp dir, probably repetive.
  
            // create write stream so we have control over events
            var output = fs.createWriteStream(
              path.join(options.nodeTempDir, 'iojs-versions.json'),
            );
  
            request.get('https://iojs.org/dist/index.json').pipe(output);
  
            output.on('close', function() {
              _log('done');
              var f = fs.readFileSync(
                path.join(options.nodeTempDir, 'iojs-versions.json'),
              );
              f = JSON.parse(f);
              version = f[0].version.replace('v', '');
  
              _log('iojs latest => ' + version);
  
              // continue down along the async road
              next();
            });
          } else {
            next();
          }
        }
docs: check relevant options