Laravel Mass assignment -

I wanted to use migration with a mass assignment. When I do this, I get the error message "Mass Assessment", I updated my class with this code:

  safe $ fillable = array ('title', 'body ',' Published_at ');  

When I do this:

  app  carbon  

I still get the same mass assignment exception. Do i miss something

I just exit the Tinker mode and update a composer. Then it worked perfectly well