class Travis::Tools::Github

def possible_tokens(&block)
  return block[github_token] if github_token
  if auto_token
    git_tokens(&block)
    hub_tokens(&block)
    oauth_file_tokens(&block)
    github_for_mac_token(&block)
    issuepost_token(&block)
    composer_token(&block)
  end
  if github_token || auto_token
    after_tokens.call
  elsif login_header
    login_header.call
  end
end