diff --git a/src/main/org/apache/tools/ant/property/GetProperty.java b/src/main/org/apache/tools/ant/property/GetProperty.java
index 2ca2baa12..c08808aa6 100644
--- a/src/main/org/apache/tools/ant/property/GetProperty.java
+++ b/src/main/org/apache/tools/ant/property/GetProperty.java
@@ -17,7 +17,10 @@
  */
 package org.apache.tools.ant.property;
 
-/** Interface to a class (normally PropertyHelper) to get a property */
+/**
+ * Interface to a class (normally PropertyHelper) to get a property.
+ * @since Ant 1.8.0
+ */
 public interface GetProperty {
     /**
      * Returns the value of a property if it is set.
diff --git a/src/main/org/apache/tools/ant/property/NullReturn.java b/src/main/org/apache/tools/ant/property/NullReturn.java
index 2012afeea..0762d86a8 100644
--- a/src/main/org/apache/tools/ant/property/NullReturn.java
+++ b/src/main/org/apache/tools/ant/property/NullReturn.java
@@ -17,7 +17,10 @@
  */
 package org.apache.tools.ant.property;
 
-/** Class to represent a null and to stop the chain of lookups. */
+/**
+ * Class to represent a null and to stop the chain of lookups.
+ * @since Ant 1.8.0
+ */
 public final class NullReturn {
     /** a value to use in a property helper to stop looking properties */
     public static final NullReturn NULL = new NullReturn();
@@ -25,5 +28,11 @@ public final class NullReturn {
     /** Private constructor */
     private NullReturn() {
     }
-}
 
+    /**
+     * {@inheritDoc}
+     */
+    public String toString() {
+        return String.valueOf(null);
+    }
+}
diff --git a/src/main/org/apache/tools/ant/property/ParseNextProperty.java b/src/main/org/apache/tools/ant/property/ParseNextProperty.java
index 72dda73e1..c39118daa 100644
--- a/src/main/org/apache/tools/ant/property/ParseNextProperty.java
+++ b/src/main/org/apache/tools/ant/property/ParseNextProperty.java
@@ -21,7 +21,10 @@ import java.text.ParsePosition;
 
 import org.apache.tools.ant.Project;
 
-/** Interface to parse a property */
+/**
+ * Interface to parse a property.
+ * @since Ant 1.8.0
+ */
 public interface ParseNextProperty {
     /**
      * Get the current project.
diff --git a/src/main/org/apache/tools/ant/property/ParseProperties.java b/src/main/org/apache/tools/ant/property/ParseProperties.java
index afb258696..bac0f1cff 100644
--- a/src/main/org/apache/tools/ant/property/ParseProperties.java
+++ b/src/main/org/apache/tools/ant/property/ParseProperties.java
@@ -24,6 +24,7 @@ import org.apache.tools.ant.Project;
 
 /**
  * Parse properties using a collection of expanders.
+ * @since Ant 1.8.0
  */
 public class ParseProperties implements ParseNextProperty {
 
@@ -37,8 +38,7 @@ public class ParseProperties implements ParseNextProperty {
      * @param expanders a sequence of exapanders
      * @param getProperty property resolver.
      */
-    public ParseProperties(
-        Project project, Collection expanders, GetProperty getProperty) {
+    public ParseProperties(Project project, Collection expanders, GetProperty getProperty) {
         this.project = project;
         this.expanders = expanders;
         this.getProperty = getProperty;
diff --git a/src/main/org/apache/tools/ant/property/PropertyExpander.java b/src/main/org/apache/tools/ant/property/PropertyExpander.java
index 0fe44ee06..48d256a5b 100644
--- a/src/main/org/apache/tools/ant/property/PropertyExpander.java
+++ b/src/main/org/apache/tools/ant/property/PropertyExpander.java
@@ -21,7 +21,10 @@ import org.apache.tools.ant.PropertyHelper;
 
 import java.text.ParsePosition;
 
-/** Interface to a class (normally PropertyHelper) to get a property */
+/**
+ * Interface to a class (normally PropertyHelper) to get a property.
+ * @since Ant 1.8.0
+ */
 public interface PropertyExpander extends PropertyHelper.Delegate {
     /**
      * Parse the next property name.
@@ -30,7 +33,6 @@ public interface PropertyExpander extends PropertyHelper.Delegate {
      * @param parseNextProperty parse next property
      * @return parsed String if any, else <code>null</code>.
      */
-    String parsePropertyName(
-        String s, ParsePosition pos, ParseNextProperty parseNextProperty);
+    String parsePropertyName(String s, ParsePosition pos, ParseNextProperty parseNextProperty);
 }
 
diff --git a/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java b/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java
index 2ec972425..ab3b9a192 100644
--- a/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java
+++ b/src/main/org/apache/tools/ant/property/ResolvePropertyMap.java
@@ -27,12 +27,13 @@ import org.apache.tools.ant.Project;
 import org.apache.tools.ant.BuildException;
 
 /**
- *  Class to resolve properties in a map.
+ * Class to resolve properties in a map.
+ * @since Ant 1.8.0
  */
 public class ResolvePropertyMap implements GetProperty {
-    private final Set       seen = new HashSet();
+    private final Set seen = new HashSet();
     private final ParseProperties parseProperties;
-    private final GetProperty    master;
+    private final GetProperty master;
     private Map map;
 
     /**
@@ -41,8 +42,7 @@ public class ResolvePropertyMap implements GetProperty {
      * @param master the master property holder (usually PropertyHelper)
      * @param expanders a collection of expanders (usually from PropertyHelper).
      */
-    public ResolvePropertyMap(
-        Project project, GetProperty master, Collection expanders) {
+    public ResolvePropertyMap(Project project, GetProperty master, Collection expanders) {
         this.master = master;
         this.parseProperties = new ParseProperties(project, expanders, this);
     }