code: public static void isInstanceOf(Class<?> type, Object obj, String message) {
  		notNull(type, "Type to check against must not be null");
  		if (!type.isInstance(obj)) {
  			instanceCheckFailed(type, obj, message);
  		}
  	}
docs: Assert that the provided object is an instance of the provided class.
  <pre class="code">Assert.instanceOf(Foo.class, foo, "Foo expected");</pre>
  @param type the type to check against
  @param obj the object to check
  @param message a message which will be prepended to provide further context.
  If it is empty or ends in ":" or ";" or "," or ".", a full exception message
  will be appended. If it ends in a space, the name of the offending object's
  type will be appended. In any other case, a ":" with a space and the name
  of the offending object's type will be appended.
  @throws IllegalArgumentException if the object is not an instance of type