allow for no input stream as long as an ID is given
diff --git a/bundles/org.eclipse.wst.sse.core/src/org/eclipse/wst/sse/core/ModelManagerImpl.java b/bundles/org.eclipse.wst.sse.core/src/org/eclipse/wst/sse/core/ModelManagerImpl.java
index 9eecb8f..05b3b4f 100644
--- a/bundles/org.eclipse.wst.sse.core/src/org/eclipse/wst/sse/core/ModelManagerImpl.java
+++ b/bundles/org.eclipse.wst.sse.core/src/org/eclipse/wst/sse/core/ModelManagerImpl.java
@@ -1189,10 +1189,7 @@
 
 	public synchronized IStructuredModel getModelForEdit(String id, InputStream inputStream, URIResolver resolver) throws IOException {
 		if (id == null) {
-			throw new IllegalArgumentException("Program Error: filename may not be null"); //$NON-NLS-1$
-		}
-		if (inputStream == null) {
-			throw new IllegalArgumentException("Program Error: model input stream may not be null"); //$NON-NLS-1$
+			throw new IllegalArgumentException("Program Error: id may not be null"); //$NON-NLS-1$
 		}
 
 		InputStream istream = Utilities.getMarkSupportedStream(inputStream);