### Question:
ConfigurationProcessorBuilder { public ConfigurationProcessorBuilder setConfigurationLoader(ConfigurationLoader configurationLoader) { if (configurationLoader == null) { throw new NullPointerException("configurationLoader must not be null"); } this.configurationLoader = configurationLoader; return this; } ConfigurationProcessorBuilder(); ConfigurationProcessorBuilder addConfigurationParser(ConfigurationParser configurationParser); ConfigurationProcessorBuilder addConfigurationParsers(List<ConfigurationParser> configurationParsers); ConfigurationProcessorBuilder setConfigurationLoader(ConfigurationLoader configurationLoader); ConfigurationProcessor build();  }### Answer:
@Test public void setConfigurationLoader() { new ConfigurationProcessorBuilder().setConfigurationLoader(() -> null); }
@Test(expected = NullPointerException.class) public void setConfigurationLoaderNull() { new ConfigurationProcessorBuilder().setConfigurationLoader(null); fail(); }