### Question:
GenesisConfigFile { public String getDifficulty() { return getRequiredString("difficulty"); } private  GenesisConfigFile(final ObjectNode config); static GenesisConfigFile mainnet(); static ObjectNode mainnetJsonNode(); static GenesisConfigFile development(); static GenesisConfigFile fromConfig(final String jsonString); static GenesisConfigFile fromConfig(final ObjectNode config); GenesisConfigOptions getConfigOptions(); GenesisConfigOptions getConfigOptions(final Map<String, String> overrides); Stream<GenesisAllocation> streamAllocations(); String getParentHash(); String getDifficulty(); String getExtraData(); long getGasLimit(); String getMixHash(); String getNonce(); Optional<String> getCoinbase(); long getTimestamp(); List<Long> getForks(); static final GenesisConfigFile DEFAULT; }### Answer:
@Test public void shouldGetDifficulty() { assertThat(configWithProperty("difficulty", "1234").getDifficulty()).isEqualTo("1234"); }