@Test
    public void testUnionOfNone() {
        final Set<String> union = union(TreeSet::new);

        assertEquals(emptySet(), union);
        assertEquals(TreeSet.class, union.getClass());
    }
Expectation setter for multiple reads where each one reads random bytes to the buffer.

@param channelMock           The mocked FileChannel object
@param bufferSize            The buffer size
@return Expected buffer string
@throws IOException          If an I/O error occurs
clients/src/test/java/org/apache/kafka/common/utils/UtilsTest.java