*** old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.options/src/org/graalvm/options/OptionValues.java	Mon Jun 26 15:43:55 2017
--- new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.options/src/org/graalvm/options/OptionValues.java	Mon Jun 26 15:43:55 2017

*** 39,55 ****
--- 39,70 ----
      OptionDescriptors getDescriptors();
  
      /**
       * Sets the value of {@code optionKey} to {@code value}.
       *
+      * @throws IllegalArgumentException if the given value is not {@link OptionType#validate(Object)
+      *             validated} by the {@link OptionKey#getType() option type} of the key. Please note
+      *             that the operation does not fail if the option key is not described by any of the
+      *             associated {@link #getDescriptors() descriptors}.
+      *
       * @since 1.0
       */
      <T> void set(OptionKey<T> optionKey, T value);
  
      /**
!      * Returns the value of a given option. Returns <code>null</code> if the option does not exist.
!      * Returns the value of a given option. If no value is set or the key is not described by any
+      * {@link #getDescriptors() descriptors} the {@link OptionType#getDefaultValue() default value}
+      * of the given key is returned.
       *
       * @since 1.0
       */
      <T> T get(OptionKey<T> optionKey);
  
+     /**
+      * Determines if a value for {@code optionKey} has been {@link #set} in this set of option
+      * values.
+      *
+      * @since 1.0
+      */
+     boolean hasBeenSet(OptionKey<?> optionKey);
+ 
  }