def self.create_from_hash(registration_hash)
    unless registration_hash || resigration_hash.empty?
      return nil
    end

    provider = registration_hash[:provider]
    info = registration_hash[:info]

    user = User.new

    if info.password
      user.password = info.password
    else
      user.password = Devise.friendly_token[0,20]
    end
    user.password_confirmation = user.password

    if provider == "seznam" || provider == "open_id"
      user.email = info.nickname
    else
      user.email = info.email
    end

    # if data.first_name && info.last_name
    #   user.first_name = info.first_name if user.first_name.blank?
    #   user.last_name  = info.last_name  if user.last_name.blank?
    # elsif data.name
    #   user.full_name  = info.name if user.full_name.blank?
    #   user.first_name = info.name.split(' ')[0] if user.first_name.blank?
    #   user.last_name  = info.name.split(' ')[1] if user.last_name.blank?
    # end

    # twitter: čtverec 48x48; odstranit "_normal" ze stringu pro plnou velikost obrázku
    # facebook: čtverec 50x50; dál už se s tím nic nedá dělat
    # user.image = info.image if user.image.blank?

    # user.gender = registration_hash['extra']['gender'] if user.gender.blank?

    if registration_hash[:skip_confirmation] == true
      # user.confirm!
    end

    user
  end