@Test
public void shouldLogErrorMessageGivenSupplier() {

  // Given:
  when(innerLogger.isErrorEnabled()).thenReturn(true);
  // When:
  logger.error(msgSupplier);
  // Then:
  verify(msgSupplier, times(1)).get();
  verify(innerLogger, times(1)).error(eq(LOG_MSG), captor.capture());
  assertThat(captor.getValue().getMessage(), is(msg));
}