function(done) {
			crypto.randomBytes(20, function(err, buffer) {
				var token = buffer.toString('hex');
				done(err, token);
			});
		}
function(done) {
			crypto.randomBytes(20, function(err, buffer) {
				var token = buffer.toString('hex');
				done(err, token);
			});
		}
function ( done ) { crypto . randomBytes ( 20 , function ( err , buffer ) { var token = buffer . toString ( 'hex' ) ; done ( err , token ) ; } ) ; }
Generate random token
Generate random token