.base_url               Returns the base url of the Hacker News API
.send_request           Sends a request to the specified url and
                        retrieves it's content.
add_json_extension      Adds the json extension to the given url
add_path                Adds the given path to the given url
assert                  Asserts a given expression and throws an error
                        if it returns FALSE
assert_ids              Checks whether ids are correctly defined. If
                        not throws an error
assert_max_items        Checks whether max_items is correctly defined.
                        If not throws an error
comment_to_dataframe_row
                        Converts comment to a dataframe row
create_hn_api_response
                        Creates an object representing a response from
                        the Hacker News API
create_hn_item          Creates an object representing Hacker News item
create_hn_user          Creates an object representing Hacker News user
create_request_url      Creates a request url based on the given base
                        url and passed paths. The json extensions is
                        added automatically.
default_if_null         return specified variable or default value if
                        specified variable is null
get_best_stories        Hacker News best stories
get_best_stories_ids    Hacker News best stories ids
get_comments            Hacker News nested comments
get_comments_with_root
                        Hacker News nested comments with root comment
get_content             Retrieves the response content
get_item_by_id          Get Hacker News by Id
get_items_by_ids        Get Hacker News by ids
get_latest_ask_stories
                        Hacker News latest ask stories
get_latest_ask_stories_ids
                        Hacker News latest ask stories ids
get_latest_job_stories
                        Hacker News latest job stories
get_latest_job_stories_ids
                        Hacker News latest job stories ids
get_latest_show_stories
                        Hacker News latest show stories
get_latest_show_stories_ids
                        Hacker News latest show stories ids
get_max_item_id         Hacker News item largest id
get_new_stories         Hacker News newest stories
get_new_stories_ids     Hacker News newest stories ids
get_top_stories         Hacker News top stories
get_top_stories_ids     Hacker News top stories ids
get_updates             Hacker News updated profiles
get_user_by_username    Get Hacker News user
is_hn_api_response      Checks whether the given object is of the class
                        hn_api_response.
is_hn_item              Checks whether the given object is of the class
                        hn_item
is_hn_user              Checks whether the given object is of the class
                        hn_user
parse_json              Parses a json response
print.hn_item           Print for "hn_item" type objects
print.hn_user           Print for "hn_user" type objects
to_datetime_origin      Converts numeric value into POSIXct datetime
                        type
trim_ids_list           Selects only limited number of ids
validate_hn_api_response
                        Checks if the given response is not empty and
                        that it did not return an error http code.
validate_hn_item        Checks whether the given object is correctly
                        defined hn_item class
validate_hn_user        Checks whether the given object is correctly
                        defined hn_user class
