Represents a filter on the set of Series. This is used to query a set of series with specific properties. A filter can include ids, keys, tags and attributes. An empty filter is created and filter predicates are added. For example a filter to return series with keys myagley-1 and myagley-2 looks like this:
{@code Filter filter = new Filter(); filter.addKey("myagley-1"); filter.addKey("myagley-1"); }