class I18n::ExceptionHandler

Note that the exception handler is not called when the option :throw was given.
was caught the handler returns an error message string containing the key/scope.
MissingTranslationData exceptions are re-thrown. When a MissingTranslationData
Handles exceptions raised in the backend. All exceptions except for

def call(exception, locale, key, options) 

def call(exception, locale, key, options)
  if exception.is_a?(MissingTranslation)
    options[:rescue_format] == :html ? exception.html_message : exception.message
  elsif exception.is_a?(Exception)
    raise exception
  else
    throw :exception, exception
  end
end