index.js
function callsites() {
	var _ = Error.prepareStackTrace;
	Error.prepareStackTrace = function (_, stack) {
		return stack;
	};
	var stack = new Error().stack.slice(1);
	Error.prepareStackTrace = _;
	return stack;
}
function callsites() {
	var _ = Error.prepareStackTrace;
	Error.prepareStackTrace = function (_, stack) {
		return stack;
	};
	var stack = new Error().stack.slice(1);
	Error.prepareStackTrace = _;
	return stack;
}
function callsites ( ) { var _ = Error . prepareStackTrace ; Error . prepareStackTrace = function ( _ , stack ) { return stack ; } ; var stack = new Error ( ) . stack . slice ( 1 ) ; Error . prepareStackTrace = _ ; return stack ; }
taken from callsites module
taken from callsites module