*/
    SID getOwnerGroup() throws IOException;

    /**
     * Return the owner group SID for this file or directory
     *
     * @param resolve
     *            whether to resolve the group name
     * @return the owner group SID, <code>null</code> if not present
     * @throws IOException if an I/O error occurs
     */
    SID getOwnerGroup(boolean resolve) throws IOException;

    /**

            when(mockResource.getOwnerGroup()).thenReturn(mockSID);
            when(mockResource.getOwnerGroup(true)).thenReturn(mockSID);

            // When
            SID ownerUser1 = mockResource.getOwnerUser();
            SID ownerUser2 = mockResource.getOwnerUser(false);
            SID ownerGroup1 = mockResource.getOwnerGroup();
            SID ownerGroup2 = mockResource.getOwnerGroup(true);