code: function coverage() {
    var jscoverage = spawn(bin('jscoverage'), ['lib', 'lib-cov']);
  
    jscoverage.on('error', function(err) {
      console.error(err);
      process.exit(1);
    });
  
    jscoverage.stderr.setEncoding('utf8');
    jscoverage.stderr.on('data', function(err) {
      console.error(err);
      process.exit(1);
    });
  
    jscoverage.on('close', suite);
  }
docs: Generate coverage files
  
  @api private