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Promise.getNewLibraryCopy() -> Object

Returns a new independent copy of the Bluebird library.

This method should be used before you use any of the methods which would otherwise alter the global Bluebird object - to avoid polluting global state.

A basic example:

var Promise = require('bluebird');
var Promise2 = Promise.getNewLibraryCopy();

Promise2.x = 123;

console.log(Promise2 == Promise); // false
console.log(Promise2.x); // 123
console.log(Promise.x); // undefined

Promise2 is independent to Promise. Any changes to Promise2 do not affect the copy of Bluebird returned by require('bluebird').

In practice:

var Promise = require('bluebird').getNewLibraryCopy();

Promise.coroutine.addYieldHandler( function() { /* */ } ); // alters behavior of `Promise.coroutine()`

// somewhere in another file or module in same app
var Promise = require('bluebird');

Promise.coroutine(function*() {
    // this code is unaffected by the yieldHandler defined above
    // because it was defined on an independent copy of Bluebird