chunk                   Helper function that splits vector into chunks
                        of specific size
wp_check_date_inputs    Helper function for 'wp_trend()'
wp_date                 Package specific 'as.Date()' function
wp_day                  Function to extract the day
wp_expand_ts            Helper function for wp_trend that transforms a
                        time span into a series of months
wp_extract_data         Helper function for wp_trend
wp_friendly_load        Helper function for wp_trend that loads
                        previous saved wp_trend results
wp_friendly_save        Helper function for wp_trend
wp_month                Function to extract the month
wp_trend                Function for getting access statistics for
                        wikipedia pages
wp_wday                 Function to extract the day of the week
wp_year                 Function to extract the year
wp_yearmonth            function for getting year and month of a
                        timestamp
