lib/lazystream.js
function beforeFirstCall(instance, method, callback) {
  instance[method] = function() {
    delete instance[method];
    callback.apply(this, arguments);
    return this[method].apply(this, arguments);
  };
}
function beforeFirstCall(instance, method, callback) {
  instance[method] = function() {
    delete instance[method];
    callback.apply(this, arguments);
    return this[method].apply(this, arguments);
  };
}
function beforeFirstCall ( instance , method , callback ) { instance [ method ] = function ( ) { delete instance [ method ] ; callback . apply ( this , arguments ) ; return this [ method ] . apply ( this , arguments ) ; } ; }
Patch the given method of instance so that the callback is executed once, before the actual method is called the first time.
Patch the given method of instance so that the callback is executed once before the actual method is called the first time .