public static JavaToSqlTypeConverter javaToSqlConverter() {
    return JAVA_TO_SQL_CONVERTER;
  }
@Test
  public void shouldThrowOnUnknownJavaType() {
    // When:
    final Exception e = assertThrows(
        KsqlException.class,
        () -> javaToSqlConverter().toSqlType(double.class)
    );

    // Then:
    assertThat(e.getMessage(), containsString("Unexpected java type: " + double.class));
  }