def pattern_from(locales)
      locales = Array(locales || [])
      locales = locales.map { |locale| subpatterns_from locale }.flatten
      pattern = locales.blank? ? '*' : "{#{locales.join ','}}"
      "#{base_pattern}#{pattern}#{extension}"
    end
def pattern_from(locales)
      locales = Array(locales || [])
      locales = locales.map { |locale| subpatterns_from locale }.flatten
      pattern = locales.blank? ? '*' : "{#{locales.join ','}}"
      "#{base_pattern}#{pattern}#{extension}"
    end
Generates a glob file pattern for the specified list of locales (i.e. IETF language tags)