style: resolve style guide violations

Author: alfonsobries

src/main/java/org/arkecosystem/crypto/transactions/types/Transaction.java

@@ -4,9 +4,7 @@
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 import org.arkecosystem.crypto.encoding.Hex;
 import org.arkecosystem.crypto.identities.PrivateKey;
 import org.arkecosystem.crypto.signature.SchnorrSigner;
@@ -104,7 +102,7 @@ public boolean secondVerify(String secondPublicKey) {
 
         return verifier().verify(hash, keys, signature);
     }
-    
+
     public String toJson() {
         GsonBuilder gsonBuilder = new GsonBuilder();
         return gsonBuilder.create().toJson(this.toHashMap());

src/test/java/org/arkecosystem/crypto/signature/FixtureSignVerificationTest.java

@@ -13,7 +13,7 @@
 public class FixtureSignVerificationTest {
 
     private final String secondPassphrase = "this is a top secret second passphrase";
-    
+
     @ParameterizedTest
     @ValueSource(
             strings = {

src/test/java/org/arkecosystem/crypto/transactions/builder/MultiPaymentBuilderTest.java

@@ -5,7 +5,6 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
-
 import org.arkecosystem.crypto.transactions.types.Transaction;
 import org.junit.jupiter.api.Test;
 

src/test/java/org/arkecosystem/crypto/transactions/builder/MultiSignatureRegistrationBuilderTest.java

@@ -35,7 +35,7 @@ void build() {
                         .transaction;
 
         assertTrue(actual.verify());
-        
+
         HashMap actualHashMap = actual.toHashMap();
 
         assertNotNull(actualHashMap.get("asset"));

src/test/java/org/arkecosystem/crypto/transactions/builder/TransferBuilderTest.java

@@ -4,12 +4,9 @@
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
-
 import org.arkecosystem.crypto.enums.Fees;
-import org.arkecosystem.crypto.identities.PublicKey;
 import org.arkecosystem.crypto.transactions.types.Transaction;
 import org.junit.jupiter.api.Test;
 
@@ -70,18 +67,19 @@ void buildSecondSignature() {
 
     @Test
     void buildMultiSignature() {
-        Transaction actual = new TransferBuilder()
-                .recipient("0xb693449AdDa7EFc015D87944EAE8b7C37EB1690A")
-                .amount(133380000000L)
-                .expiration(100000)
-                .vendorField("This is a transaction from Java")
-                .nonce(3)
-                .fee(Fees.TRANSFER.getValue())
-                .multiSign("secret 1", 0)
-                .multiSign("secret 2", 1)
-                .multiSign("secret 3", 2)
-                .sign("secret 1")
-                .transaction;
+        Transaction actual =
+                new TransferBuilder()
+                        .recipient("0xb693449AdDa7EFc015D87944EAE8b7C37EB1690A")
+                        .amount(133380000000L)
+                        .expiration(100000)
+                        .vendorField("This is a transaction from Java")
+                        .nonce(3)
+                        .fee(Fees.TRANSFER.getValue())
+                        .multiSign("secret 1", 0)
+                        .multiSign("secret 2", 1)
+                        .multiSign("secret 3", 2)
+                        .sign("secret 1")
+                        .transaction;
 
         assertTrue(actual.verify());
 

src/test/java/org/arkecosystem/crypto/transactions/builder/UsernameRegistrationBuilderTest.java

@@ -4,7 +4,6 @@
 
 import java.util.HashMap;
 import java.util.List;
-
 import org.arkecosystem.crypto.transactions.types.Transaction;
 import org.junit.jupiter.api.Test;
 

src/test/java/org/arkecosystem/crypto/transactions/builder/UsernameResignationBuilderTest.java

@@ -4,7 +4,6 @@
 
 import java.util.HashMap;
 import java.util.List;
-
 import org.arkecosystem.crypto.transactions.types.Transaction;
 import org.junit.jupiter.api.Test;
 

src/test/java/org/arkecosystem/crypto/transactions/builder/ValidatorRegistrationBuilderTest.java

@@ -4,7 +4,6 @@
 
 import java.util.HashMap;
 import java.util.List;
-
 import org.arkecosystem.crypto.transactions.types.Transaction;
 import org.junit.jupiter.api.Test;
 
@@ -44,7 +43,7 @@ void buildMultiSignature() {
                         .transaction;
 
         assertTrue(actual.verify());
-        
+
         HashMap actualHashMap = actual.toHashMap();
 
         assertNotNull(actualHashMap.get("signatures"));

src/test/java/org/arkecosystem/crypto/transactions/builder/ValidatorResignationBuilderTest.java

@@ -4,7 +4,6 @@
 
 import java.util.HashMap;
 import java.util.List;
-
 import org.arkecosystem.crypto.transactions.types.Transaction;
 import org.junit.jupiter.api.Test;