PropertiesFileConfiguration extends AbstractConfiguration implements FileConfiguration { @Override public void load(String fileName) throws ConfigurationException { load(new File(fileName)); } PropertiesFileConfiguration();  PropertiesFileConfiguration(String fileName);  PropertiesFileConfiguration(String fileName, Charset encoding);  PropertiesFileConfiguration(File file);  PropertiesFileConfiguration(File file, Charset encoding);  PropertiesFileConfiguration(InputStream inStream);  PropertiesFileConfiguration(InputStream inStream, Charset encoding);  PropertiesFileConfiguration(Properties properties); @Override Configuration subset(String prefix); @Override Configuration strippedSubset(String prefix); @Override boolean isEmpty(); @Override boolean containsKey(String key); @Override void setProperty(String key, String value); @Override void clear(); @Override void clearProperty(String key); @Override Iterable<String> getKeys(); @Override String getProperty(String key); @Override String getProperty(String key, String defaultValue); @Override Charset getEncoding(); @Override void setEncoding(Charset encoding); static PropertiesFileConfiguration merge(Configuration ... configs); @Override void load(String fileName); @Override void load(File file); @Override void load(InputStream inStream); @Override void load(Reader reader); void load(Properties properties); @Override String toString();  }
@Test public void testEmptyReader() throws Exception { Throwable t = assertThrows(ConfigurationException.class, () -> config.load(new File("/does/not/exist"))); assertThat(t.getCause(), IsInstanceOf.instanceOf(FileNotFoundException.class)); }