Improve NameTree documentation
diff --git a/src/main/java/com/intel/jndn/utils/NameTree.java b/src/main/java/com/intel/jndn/utils/NameTree.java
index 8ae4fcc..a07c791 100644
--- a/src/main/java/com/intel/jndn/utils/NameTree.java
+++ b/src/main/java/com/intel/jndn/utils/NameTree.java
@@ -20,26 +20,65 @@
 import java.util.Optional;
 
 /**
+ * Represent a tree of nodes, branching based on their component values
+ *
  * @author Andrew Brown, andrew.brown@intel.com
  */
 public interface NameTree<T> {
-  Optional<T> content();
-
-  Name.Component lastComponent();
-
+  /**
+   * @return the full name leading from the root of the tree to this node
+   */
   Name fullName();
 
+  /**
+   * @return the last component identifying this node; e.g. if the {@link #fullName()} is {@code /a/b/c} for this node,
+   * this method must return {@code c}
+   */
+  Name.Component lastComponent();
+
+  /**
+   * @return the optional content stored at this location in the tree
+   */
+  Optional<T> content();
+
+  /**
+   * @return the children of this node or an empty collection
+   */
   Collection<NameTree<T>> children();
 
+  /**
+   * @return the parent of this node; note that calling this on the root node will return {@code null}
+   */
   NameTree<T> parent();
 
+  /**
+   * @param name the full name leading to the location in the tree; if intervening nodes do not yet exist, they will be
+   * created
+   * @param content the content to store at this location; this may overwrite previously existing content, much like a
+   * {@link java.util.Map}
+   * @return a reference to the node inserted
+   */
   NameTree<T> insert(Name name, T content);
 
+  /**
+   * @param query the name to use as a path through the tree
+   * @return an optional node; if there is no node at the end of the query, the {@link Optional} will be empty
+   */
   Optional<NameTree<T>> find(Name query);
 
+  /**
+   * @param name the name to use as a path through the tree
+   * @return the removed node or an empty {@link Optional} if the node was not found
+   */
   Optional<NameTree<T>> delete(Name name);
 
+  /**
+   * @return the count of all nodes in the tree below this one that are non-empty (e.g. have some content)
+   */
   int count();
 
+  /**
+   * Remove all nodes beneath this one; will have no effect on a leaf node
+   */
   void clear();
 }