def partnership(first_username, second_username, options={})
      raise 'Error: Param first_username is nil!' if first_username.nil?
      raise 'Error: Param second_username is nil!' if second_username.nil?

      url = url_for_path(partnership_path(first_username, second_username))
      url = append_query_params(url, options)
      client.get(url, options) do |response|
        a_hash = parse(response)
        Resource::Partnership.from_coach a_hash
      end
    end
def partnership(first_username, second_username, options={})
      raise 'Error: Param first_username is nil!' if first_username.nil?
      raise 'Error: Param second_username is nil!' if second_username.nil?

      url = url_for_path(partnership_path(first_username, second_username))
      url = append_query_params(url, options)
      client.get(url, options) do |response|
        a_hash = parse(response)
        Resource::Partnership.from_coach a_hash
      end
    end
Retrieves a partnership by the first username and second username.

 @param [String] first_username
 @param [String] second_username
 @param [Hash] options
 @return [Partnership]

 ====Examples
 @example
   partnership = @coach.partnership 'arueedlinger', 'asarteam5'