assertTrue(renewed instanceof SmbRenewableCredentials, "renewed credentials should still be SmbRenewableCredentials");
        } else {
            assertNull(renewed, "renew() may return null for failed renewal");
        }
    }

    @Test
    @DisplayName("Mockito: verify renew() interaction and return value")

    its dependencies and the rest of the system.
-   Rarely, If the tests fail at this stage, we cannot merge the code.
-   If needed, we may come to you to make some changes. At times, it may not be
    you, it may be us who may have hit a snag. Please be patient while we work
    to fix this.
-   Once the internal tests pass, we go ahead and merge the code internally as
    well as externally on GitHub.

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