1 files changed, 26 insertions, 0 deletions
diff --git a/bundles/org.eclipse.equinox.metatype/src/org/eclipse/equinox/metatype/Extendable.java b/bundles/org.eclipse.equinox.metatype/src/org/eclipse/equinox/metatype/Extendable.java
index 4f6069ec5..dc93171cc 100644
--- a/bundles/org.eclipse.equinox.metatype/src/org/eclipse/equinox/metatype/Extendable.java
+++ b/bundles/org.eclipse.equinox.metatype/src/org/eclipse/equinox/metatype/Extendable.java
@@ -11,12 +11,38 @@ import java.util.Map;
 import java.util.Set;
 
 /**
+ * An interface marking an object as possibly having extension attributes. An
+ * attribute is a property that describes the object. An extension attribute is
+ * a custom property added by a third party.
+ * 
+ * The use case for this interface was to expose third party attributes
+ * included in the metadata XML on elements that support <anyAttribute/>
+ * according to the metatype schema, but it is not strictly limited to this use.
  * 
  * @since 1.2
  *
  */
 public interface Extendable {
+	/**
+	 * Returns a {@link Map map} containing the extension attributes for the
+	 * specified {@link #getExtensionUris() URI}. The map key is the attribute
+	 * name, and the map value is the attribute value. If the specified URI has
+	 * no extension attributes, the map will be {@code null}.
+	 * 
+	 * @param uri - The URI for which extension attributes are desired.
+	 * @return A map containing the extension attributes for the specified URI,
+	 *         or {@code null} if there are none.
+	 * @see #getExtensionUris()
+	 */
 	Map<String, String> getExtensionAttributes(String uri);
 
+	/**
+	 * Returns the {@link Set set} of URIs for which {@link 
+	 * #getExtensionAttributes(String) extension attributes} exist. It is
+	 * guaranteed that there is at least one extension attribute for each URI
+	 * in the set. 
+	 * @return A set containing the URIs for which extension attributes exist.
+	 * @see #getExtensionAttributes(String)
+	 */
 	Set<String> getExtensionUris();
 }