[Lang] Fix nullable annotations
diff --git a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/lang/ObjectUtils.java b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/lang/ObjectUtils.java
index a0329ab..9b0cf6b 100644
--- a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/lang/ObjectUtils.java
+++ b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/lang/ObjectUtils.java
@@ -96,7 +96,7 @@
 			this.sb.append(number);
 		}
 		
-		public final void append(final String valueFormat, final Object... valueArgs) {
+		public final void appendFormat(final String valueFormat, final @Nullable Object... valueArgs) {
 			Formatter formatter= this.formatter;
 			if (formatter == null) {
 				formatter= new Formatter(this.sb, Locale.ENGLISH);
@@ -228,10 +228,10 @@
 			}
 		}
 		
-		public void addProp(final String name, final String valueFormat, final Object... valueArgs) {
+		public void addProp(final String name, final String valueFormat, final @Nullable Object... valueArgs) {
 			addProp(name);
 			
-			append(valueFormat, valueArgs);
+			appendFormat(valueFormat, valueArgs);
 		}
 		
 		public String build() {