@Test
    public void testUnauthenticatedApiVersionsRequestOverPlaintextHandshakeVersion0() throws Exception {
        testUnauthenticatedApiVersionsRequest(SecurityProtocol.SASL_PLAINTEXT, (short) 0);
    }
Tests that Kafka ApiVersionsRequests are handled by the SASL server authenticator
prior to SASL handshake flow and that subsequent authentication succeeds
when transport layer is PLAINTEXT. This test simulates SASL authentication using a
(non-SASL) PLAINTEXT client and sends ApiVersionsRequest straight after
connection to the server is established, before any SASL-related packets are sent.
This test is run with SaslHandshake version 0 and no SaslAuthenticate headers.
clients/src/test/java/org/apache/kafka/common/security/authenticator/SaslAuthenticatorTest.java