code: public void removePermission(String identity) throws RepositoryException, AccessControlException
     {
        checkValid();
  
        if (!isNodeType(Constants.EXO_PRIVILEGEABLE))
        {
           throw new AccessControlException("Node is not exo:privilegeable " + getPath());
        }
  
        checkPermission(PermissionType.CHANGE_PERMISSION);
  
        AccessControlList acl = new AccessControlList(getACL().getOwner(), getACL().getPermissionEntries());
        acl.removePermissions(identity);
        setACL(acl);
        updatePermissions(acl);
     }
docs: {@inheritDoc}