app/mailers/thredded/base_mailer.rb
def find_record(klass, id_or_record)
      # Check by name because in development the Class might have been reloaded after id was initialized
      id_or_record.class.name == klass.name ? id_or_record : klass.find(id_or_record)
    end
def find_record(klass, id_or_record)
      # Check by name because in development the Class might have been reloaded after id was initialized
      id_or_record.class.name == klass.name ? id_or_record : klass.find(id_or_record)
    end
Find a record by ID, or return the passed record.
 @param [Class<ActiveRecord::Base>] klass
 @param [Integer, String, klass] id_or_record
 @return [klass]