code: function __requireLibCore(libName) {
    var window = global.window;
    if (!window) return; // Must run in a browser. Todo: add commonjs support
  
    // get library from browser globals if we can
    var lib = window[libName];
    if (lib) return lib;
  
    // if require exists, maybe require can get it.
    // This method is synchronous so it can't load modules with AMD.
    // It can only obtain modules from require that have already been loaded.
    // Developer should bootstrap such that the breeze module
    // loads after all other libraries that breeze should find with this method
    // See documentation
    var r = window.require;
    if (r) { // if require exists
      if (r.defined) { // require.defined is not standard and may not exist
        // require.defined returns true if module has been loaded
        return r.defined(libName) ? r(libName) : undefined;
      } else {
        // require.defined does not exist so we have to call require('libName') directly.
        // The require('libName') overload is synchronous and does not load modules.
        // It throws an exception if the module isn't already loaded.
        try {
          return r(libName);
        } catch (e) {
          // require('libName') threw because module not loaded
          return;
        }
      }
    }
  }
docs: Returns the 'libName' module if loaded or else returns undefined