@Test
public void initialBufferSizeBadValues() {

	assertThatExceptionOfType(IllegalArgumentException.class)
			.isThrownBy(() -> conf.initialBufferSize(0))
			.as("rejects 0")
			.withMessage("initialBufferSize must be strictly positive");
	assertThatExceptionOfType(IllegalArgumentException.class)
			.isThrownBy(() -> conf.initialBufferSize(-1))
			.as("rejects negative")
			.withMessage("initialBufferSize must be strictly positive");
}