Per javadoc of MethodHandles.publicLookup() https://docs.oracle.com/javase/8/docs/api/java/lang/invoke/MethodHandles.html#publicLookup-- "As a matter of pure convention, the lookup class of this lookup object will be Object."

import java.lang.invoke.MethodHandles;

class PublicLookupClass {
   public static void main(String[] args) {
       Class cl = MethodHandles.publicLookup().lookupClass();
       System.out.println(cl);
       System.out.println(cl.getClassLoader());
   }
}

Running the above class with jake and jdk9 produces result as follows:

$ /cygdrive/d/src/jake/build/windows-x86_64-normal-server-release/images/jdk/bin/java PublicLookupClass
class Unnamed
java.lang.invoke.MethodHandles$LookupHelper$1@721e0f4f

$ /cygdrive/d/src/jdk9-dev/build/windows-x86_64-normal-server-release/images/jdk/bin/java PublicLookupClass
class java.lang.Object
null