generate post_time_on_subreddit_PageType for a single post, within a given period

[natematias]

• within a given period
• check to see if consistent records were kept for PageType
• if so, generate post_time_on_subreddit (minutes???) (the amount of time a post was visible on the PageType page for that subreddit)
• if a post disappears, take the total time it was on top at any moment
• return the value (no need to store this)

(other thing to look at, at least, will be ranking. Do we want to take ranking into account? I don't know)

[natematias]

If a gap is spotted:

• return the size of the gap
• do not include the gap in the count of minutes

Definition of a gap: 2x the expected/typical interval (for snapshots of a particular subreddit_id pagetype subredditpage in the given time period)

The sum duration of all gaps might be calculated by:

• making a list of all intervals between snapshots
• identifying outliers of those intervals (perhaps by rounding the intervals to the nearest minute and looking at what interval is most common)
• returning the sum of those outliers Maybe ???