global

def load(cache_file = nil)

the cache version is different than this version.
file does not exist, if the file cannot be loaded, or if the data in
the environment variable +RUBY_MIME_TYPES_CACHE+. Returns +nil+ if the
Attempts to load the cache from the file provided as a parameter or in 
def load(cache_file = nil)
  cache_file ||= ENV["RUBY_MIME_TYPES_CACHE"]
  return nil unless cache_file && File.exist?(cache_file)
  cache = Marshal.load(File.binread(cache_file))
  if cache.version == MIME::Types::Data::VERSION
    Marshal.load(cache.data)
  else
    MIME::Types.logger.error <<-WARNING.chomp.strip
      Could not load MIME::Types cache: invalid version
    WARNING
    nil
  end
rescue => e
  MIME::Types.logger.error <<-WARNING.chomp.strip
    Could not load MIME::Types cache: #{e}
  WARNING
  nil
end