### Question:
EnvironmentVariableProviderFactoryImpl implements EnvironmentVariableProviderFactory { @Override public EnvironmentVariableProvider create() { return new EnvironmentVariableProvider(); }  @Override EnvironmentVariableProvider create();  }### Answer:
@Test public void create() { EnvironmentVariableProviderFactoryImpl factory = new EnvironmentVariableProviderFactoryImpl(); assertThat(factory.create()).isExactlyInstanceOf(EnvironmentVariableProvider.class); }