Fixed and simplified 'language not supported' formatting
diff --git a/gremlin-groovy/src/main/java/org/apache/tinkerpop/gremlin/groovy/engine/ScriptEngines.java b/gremlin-groovy/src/main/java/org/apache/tinkerpop/gremlin/groovy/engine/ScriptEngines.java
index 1113eb5..ca3b799 100644
--- a/gremlin-groovy/src/main/java/org/apache/tinkerpop/gremlin/groovy/engine/ScriptEngines.java
+++ b/gremlin-groovy/src/main/java/org/apache/tinkerpop/gremlin/groovy/engine/ScriptEngines.java
@@ -91,8 +91,7 @@
      * Evaluate a script with {@code Bindings} for a particular language.
      */
     public Object eval(final String script, final Bindings bindings, final String language) throws ScriptException {
-        if (!scriptEngines.containsKey(language))
-            throw new IllegalArgumentException(String.format("Language [%s] not supported", language));
+        checkLanguageIsSupported(language);
 
         awaitControlOp();
 
@@ -107,8 +106,7 @@
      */
     public Object eval(final Reader reader, final Bindings bindings, final String language)
             throws ScriptException {
-        if (!scriptEngines.containsKey(language))
-            throw new IllegalArgumentException("Language [%s] not supported");
+        checkLanguageIsSupported(language);
 
         awaitControlOp();
 
@@ -412,4 +410,10 @@
         all.putAll(bindings);
         return all;
     }
+
+    private void checkLanguageIsSupported(final String language) {
+        if (!scriptEngines.containsKey(language)) {
+            throw new IllegalArgumentException(String.format("Language [%s] not supported", language));
+        }
+    }
 }