Move types into separate module

disk/src/merge.rs

@@ -1,9 +1,10 @@
-use crate::agg::streams::Appendable;
-use crate::binned::{EventsNodeProcessor, PushableIndex, WithLen, WithTimestamps};
 use err::Error;
 use futures_core::Stream;
 use futures_util::StreamExt;
-use items::{LogItem, RangeCompletableItem, Sitemty, StatsItem, StreamItem};
+use items::{
+    Appendable, EventsNodeProcessor, LogItem, PushableIndex, RangeCompletableItem, Sitemty, StatsItem, StreamItem,
+    WithLen, WithTimestamps,
+};
 use netpod::log::*;
 use netpod::EventDataReadStats;
 use std::collections::VecDeque;