remove unused method
diff --git a/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/content/java/JavaPersistentType.java b/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/content/java/JavaPersistentType.java
index a73ff12..2313dce 100644
--- a/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/content/java/JavaPersistentType.java
+++ b/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/content/java/JavaPersistentType.java
@@ -827,15 +827,6 @@
 		return this.parentPersistentType;
 	}
 
-	private String superclassTypeSignature() {
-		try {
-			return this.jdtType().getSuperclassTypeSignature();
-		}
-		catch (JavaModelException ex) {
-			throw new RuntimeException(ex);
-		}
-	}
-
 	/**
 	 * Return the AccessType currently implied by the Java source code:
 	 *     - if only Fields are annotated => FIELD