/**
  * Creates the content for the migration file.
  *
  * @param  $class_name string
  * @param  $table_name string
  * @param  $args array
  * @return void
  */
 protected function generate_migration($class_name, $table_name, $args)
 {
     // Figure out what type of event is occuring. Create, Delete, Add?
     list($table_action, $table_event) = $this->parse_action_type($class_name);
     // Now, we begin creating the contents of the file.
     Template::new_class($class_name);
     /* The Migration Up Function */
     $up = $this->migration_up($table_event, $table_action, $table_name, $args);
     /* The Migration Down Function */
     $down = $this->migration_down($table_event, $table_action, $table_name, $args);
     // Add both the up and down function to the migration class.
     Content::add_after('{', $up . $down);
     return $this->prettify();
 }