lib/foursquare2/users.rb
def user_friend_request(user_id, options={})
      response = connection.post do |req|
        req.url "users/#{user_id}/request", options
      end
      return_error_or_body(response, response.body.response)
    end
def user_friend_request(user_id, options={})
      response = connection.post do |req|
        req.url "users/#{user_id}/request", options
      end
      return_error_or_body(response, response.body.response)
    end
Request friendship with a user

 @param [String] user_id - The user to request friendship with.