lib/common/index.js
function (options, must) {
    if (must) {
      for (var prop in must) {
        if (options[prop] === void 0 || options[prop] === null) {
          options[prop] = must[prop];
        }
      }
    }
    return options;
  }
function (options, must) {
    if (must) {
      for (var prop in must) {
        if (options[prop] === void 0 || options[prop] === null) {
          options[prop] = must[prop];
        }
      }
    }
    return options;
  }
function ( options , must ) { if ( must ) { for ( var prop in must ) { if ( options [ prop ] === void 0 || options [ prop ] === null ) { options [ prop ] = must [ prop ] ; } } } return options ; }
Ensures that options at least contains propties and values from must
if they're not already defined and not null.
Differs from underscore by replacing
undefined *or null* falsies, and only one defaults source allowed.
Ensures that options at least contains propties and values from must if they re not already defined and not null . Differs from underscore by replacing undefined * or null * falsies and only one defaults source allowed .