code: public void removeEntry(AclEntry entry) {
      switch (entry.getType()) {
        case NAMED_USER:
          mNamedUserActions.remove(entry.getSubject());
          return;
        case NAMED_GROUP:
          mNamedGroupActions.remove(entry.getSubject());
          return;
        case MASK:
          if (hasExtended()) {
            throw new IllegalStateException(
                "Deleting the mask for extended ACLs is not allowed. entry: " + entry);
          } else {
            mMaskActions = new AclActions();
          }
          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