title: Wrong number of arguments (2 for 3)
body: <p>it is the first time to encounter this error in rails and i really don't know where is it coming from here is the function implementation :</p>
  
  <pre><code>   def self.send (sender,recivers,content)
              recivers.each do |reciver|
                  @notification = Notification.new
                  @notification.sender= sender
                  @notification.user = reciver
                  @notification.body = content 
                  @notification.save
              end 
  
      end 
  </code></pre>
  
  <p>and here is how am calling it : </p>
  
  <pre><code>def after_create(announcment)
      instructor_id = announcment.course.instructor_id
      sender = User.find_by_id(instructor_id)
      students = announcment.course.users
      body = announcment.announcment
      coures_name = announcment.course.name 
      Notification.send(sender,students,body)
      UserMailer.notify_students_course(students,coures_name)
  end
  </code></pre>