### Question:
HCSCore { public HCSCore builder() throws Exception{ if( ! this.initialised) { init("", "./config/config.yaml", "./config/.env"); } return this; } HCSCore(); HCSCore builder(); HCSCore builder(String appId); HCSCore builder(String appId, String configFilePath, String environmentFilePath); HCSCore addOrUpdateAppParticipant(String appId, String theirEd25519PubKeyForSigning, String sharedSymmetricEncryptionKey); HCSCore removeAppParticipant(String appId); HCSCore withMessageSignature(boolean signMessages); HCSCore withEncryptedMessages(boolean encryptMessages); HCSCore withMessageEncryptionKey(byte[] messageEncryptionKey); HCSCore withMessageSigningKey(Ed25519PrivateKey messageSigningKey); HCSCore withKeyRotation(boolean keyRotation, int frequency); HCSCore withNodeMap(Map<AccountId, String> nodeMap); HCSCore withOperatorAccountId(AccountId operatorAccountId); HCSCore withOperatorKey(Ed25519PrivateKey operatorKey); HCSCore withTopic(Topic topic); HCSCore withTopic(String topic); HCSCore withTopicList(List<Topic> topics); boolean getSignMessages(); boolean getEncryptMessages(); byte[] getMessageEncryptionKey(); Ed25519PrivateKey getMessageSigningKey(); boolean getRotateKeys(); int getRotationFrequency(); Map<AccountId, String> getNodeMap(); AccountId getOperatorAccountId(); Ed25519PrivateKey getOperatorKey(); List<Topic> getTopics(); long getMaxTransactionFee(); String getApplicationId(); String getMirrorAddress(); boolean getCatchupHistory(); void setPersistence(SxcPersistence persistence); SxcPersistence getPersistence(); Map<String, String> getHibernateConfig(); List<ConsensusTopicId> getConsensusTopicIds(); KeyAgreement getTempKeyAgreement(); void setTempKeyAgreement(KeyAgreement tempKeyAgreement); MirrorSubscriptionInterface getMirrorSubscription();  }### Answer:
@Test public void testCoreEmptyEnvironment() throws Exception { @SuppressWarnings("unused") HCSCore hcsCore = new HCSCore().builder("0", "./src/test/resources/config.yaml", "./src/test/resources/dotenvempty.test"); }