code: public void removeEntry(AclEntry entry) {
      switch (entry.getType()) {
        case NAMED_USER:  // fall through
        case NAMED_GROUP: // fall through
        case MASK:
          if (mExtendedEntries != null) {
            mExtendedEntries.removeEntry(entry);
          }
          return;
        case OWNING_USER:  // fall through
        case OWNING_GROUP: // fall through
        case OTHER:
          throw new IllegalStateException(
              "Deleting base entry is not allowed. entry: " + entry);
        default:
          throw new IllegalStateException("Unknown ACL entry type: " + entry.getType());
      }
    }
docs: Removes the specified entry. A base entry is not allowed to be removed.
  
  @param entry the entry to be removed