diff --git a/src/main.rs b/src/main.rs
index 295d549..888688e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -122,9 +122,9 @@ fn main() {
         }
     };
 
-    let recover_tool  = Recover::new(config, input, output, map);
+    let mut recover_tool  = Recover::new(config, input, output, map);
 
-    recover_tool.run_full();
+    recover_tool.run();
 
     todo!("Recovery, Map saving, and closure of all files.");
 }
@@ -152,10 +152,25 @@ fn get_path(
 /// Get length of data stream.
 /// Physical length of data stream in bytes
 /// (multiple of sector_size, rather than actual).
-fn get_stream_length<S: Seek>(file: &mut S) -> io::Result<u64> {
-    let len = file.seek(SeekFrom::End(0))?;
+fn get_stream_length<S: Seek>(input: &mut S) -> io::Result<u64> {
+    let len = input.seek(SeekFrom::End(0))?;
 
-    let _ = file.seek(SeekFrom::Start(0));
+    let _ = input.seek(SeekFrom::Start(0));
 
     Ok(len)
+}
+
+
+#[cfg(test)]
+#[allow(unused)]
+mod tests {
+    use super::*;
+
+    // Test for get_path
+    // Need to determine how to package files to test with, or at least
+    // how to test with PathBuf present.
+    // Test must also check unwrapping of file name, not just generation.
+
+    // Test for get_stream_length
+    // Need to determine how to test with Seek-able objects.
 }
\ No newline at end of file
diff --git a/src/mapping.rs b/src/mapping.rs
index 763be02..0e60228 100644
--- a/src/mapping.rs
+++ b/src/mapping.rs
@@ -69,6 +69,37 @@ impl From<Cluster> for MapCluster {
     }
 }
 
+impl MapCluster {
+    /// Breaks apart into a vec of clusters,
+    /// each of cluster_size, excepting last.
+    pub fn subdivide(&mut self, cluster_len: usize) -> Vec<MapCluster> {
+        let domain_len = self.domain.len();
+        let mut start = self.domain.start;
+        let mut clusters: Vec<MapCluster> = vec![];
+
+        for _ in 0..(domain_len as f64 / cluster_len as f64).floor() as usize {
+            clusters.push(MapCluster {
+                domain: Domain {
+                    start: start,
+                    end: start + cluster_len,
+                },
+                stage: self.stage,
+            });
+
+            start += cluster_len;
+        }
+
+        clusters.push(MapCluster {
+            domain: Domain {
+                start: start,
+                end: self.domain.end,
+            },
+            stage: self.stage,
+        });
+
+        clusters
+    }
+}
 
 #[derive(Clone, Copy, Debug, Deserialize, PartialEq, PartialOrd)]
 pub enum Stage {
@@ -125,7 +156,7 @@ impl MapFile {
     }
 
     /// Recalculate cluster mappings.
-    fn update(&mut self, new_cluster: Cluster) {
+    fn update(&mut self, new_cluster: Cluster) -> &mut Self {
         let mut new_map: Vec<MapCluster> = vec![MapCluster::from(new_cluster.to_owned())];
 
         for map_cluster in self.map.iter() {
@@ -185,6 +216,7 @@ impl MapFile {
         }
 
         self.map = new_map;
+        self
     }
 
     /// Get current recovery stage.
@@ -266,4 +298,21 @@ impl MapFile {
         self.map = new_map;
         self
     }
+}
+
+
+#[cfg(test)]
+#[allow(unused)]
+mod tests {
+    use super::*;
+
+    // Test for MapCluster::subdivide()
+
+    // Test for MapFile::update()
+
+    // Test for MapFile::get_stage()
+
+    // Test for MapFile::get_clusters()
+
+    // Test for MapFile::defrag()
 }
\ No newline at end of file
diff --git a/src/recovery.rs b/src/recovery.rs
index 5095905..726b0ac 100644
--- a/src/recovery.rs
+++ b/src/recovery.rs
@@ -46,20 +46,30 @@ impl Recover {
     }
 
     /// Recover media from blank slate.
-    pub fn run_full(self) {}
-
-    /// Recover media given a partial recovery.
-    pub fn run_limited(self) {}
+    pub fn run(&mut self) -> &mut Self {
+        self
+    }
 
     /// Attempt to copy all untested blocks.
-    fn copy_untested(self) {
-        
+    fn copy_untested(&mut self) -> &mut Self {
+
+        self
     }
 
     /// Set buffer capacities as cluster length in bytes.
     /// Varies depending on the recovery stage.
-    fn set_buf_capacity(&mut self) {
+    fn set_buf_capacity(&mut self) -> &mut Self {
         self.buf_capacity = (self.config.sector_size * self.config.cluster_length) as usize;
+
+        self
     }
 }
 
+
+#[cfg(test)]
+#[allow(unused)]
+mod tests {
+    use super::*;
+
+    // Test for Recover::set_buf_capacity
+}
\ No newline at end of file