--- a/src/org/tmatesoft/hg/core/HgChangesetTreeHandler.java	Mon Feb 27 19:38:44 2012 +0100
+++ b/src/org/tmatesoft/hg/core/HgChangesetTreeHandler.java	Mon Mar 05 14:50:51 2012 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011 TMate Software Ltd
+ * Copyright (c) 2011-2012 TMate Software Ltd
  *  
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -22,7 +22,10 @@
 import org.tmatesoft.hg.util.Pair;
 
 /**
- *
+ * Handler to iterate file history (generally, any revlog) with access to parent-child relations between changesets.
+ * 
+ * @see HgLogCommand#execute(HgChangesetTreeHandler)
+ * 
  * @author Artem Tikhomirov
  * @author TMate Software Ltd.
  */
@@ -30,55 +33,60 @@
 	/**
 	 * @param entry access to various pieces of information about current tree node. Instances might be 
 	 * reused across calls and shall not be kept by client's code
+	 * @throws HgException allows implementers propagate errors from {@link TreeElement} or other parts of the library.
 	 * @throws HgCallbackTargetException.Wrap wrapper object for any exception user code may produce. Wrapped exception would get re-thrown with {@link HgCallbackTargetException} 
 	 * @throws CancelledException if execution of the operation was cancelled
 	 */
-	public void next(HgChangesetTreeHandler.TreeElement entry) throws HgCallbackTargetException.Wrap, CancelledException;
+	public void next(HgChangesetTreeHandler.TreeElement entry) throws HgException, HgCallbackTargetException.Wrap, CancelledException;
 
 	interface TreeElement {
 		/**
 		 * Revision of the revlog being iterated. For example, when walking file history, return value represents file revisions.
 		 * 
 		 * @return revision of the revlog being iterated.
+		 * @throws HgException to indicate failure dealing with Mercurial data
 		 */
-		public Nodeid fileRevision();
+		public Nodeid fileRevision() throws HgException;
 
 		/**
 		 * @return changeset associated with the current revision
-		 * @throws HgException indicates failure dealing with Mercurial data
+		 * @throws HgException to indicate failure dealing with Mercurial data
 		 */
 		public HgChangeset changeset() throws HgException;
 
 		/**
 		 * Lightweight alternative to {@link #changeset()}, identifies changeset in which current file node has been modified 
-		 * @return changeset {@link Nodeid} 
+		 * @return changeset {@link Nodeid revision} 
+		 * @throws HgException to indicate failure dealing with Mercurial data
 		 */
-		public Nodeid changesetRevision();
+		public Nodeid changesetRevision() throws HgException;
 
 		/**
 		 * Node, these are not necessarily in direct relation to parents of changeset from {@link #changeset()} 
 		 * @return changesets that correspond to parents of the current file node, either pair element may be <code>null</code>.
-		 * @throws HgException indicates failure dealing with Mercurial data
+		 * @throws HgException to indicate failure dealing with Mercurial data
 		 */
 		public Pair<HgChangeset, HgChangeset> parents() throws HgException;
 		
 		/**
 		 * Lightweight alternative to {@link #parents()}, give {@link Nodeid nodeids} only
 		 * @return two values, neither is <code>null</code>, use {@link Nodeid#isNull()} to identify parent not set
+		 * @throws HgException to indicate failure dealing with Mercurial data
 		 */
-		public Pair<Nodeid, Nodeid> parentRevisions();
+		public Pair<Nodeid, Nodeid> parentRevisions() throws HgException;
 
 		/**
 		 * Changes that originate from the given change and bear it as their parent. 
 		 * @return collection (possibly empty) of immediate children of the change
-		 * @throws HgException indicates failure dealing with Mercurial data
+		 * @throws HgException to indicate failure dealing with Mercurial data
 		 */
 		public Collection<HgChangeset> children() throws HgException;
 
 		/**
 		 * Lightweight alternative to {@link #children()}.
 		 * @return never <code>null</code>
+		 * @throws HgException to indicate failure dealing with Mercurial data
 		 */
-		public Collection<Nodeid> childRevisions();
+		public Collection<Nodeid> childRevisions() throws HgException;
 	}
 }
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