Make checkstyle happy

pgpainless-wot/src/main/java/org/pgpainless/wot/WebOfTrust.java

@@ -12,7 +12,6 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.function.Supplier;
 
 import org.bouncycastle.bcpg.sig.RevocationReason;
 import org.bouncycastle.openpgp.PGPPublicKey;
@@ -36,6 +35,7 @@ import org.pgpainless.wot.dijkstra.sq.CertificationSet;
 import org.pgpainless.wot.dijkstra.sq.Network;
 import org.pgpainless.wot.dijkstra.sq.Optional;
 import org.pgpainless.wot.dijkstra.sq.ReferenceTime;
+import org.pgpainless.wot.sugar.Supplier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import pgp.certificate_store.certificate.Certificate;
@@ -140,7 +140,7 @@ public class WebOfTrust implements CertificateAuthority {
         return nb.buildNetwork();
     }
 
-    private static class NetworkBuilder {
+    private static final class NetworkBuilder {
 
         // Index structures
         private final Map<OpenPgpFingerprint, KeyRingInfo> byFingerprint = new HashMap<>();

pgpainless-wot/src/main/java/org/pgpainless/wot/sugar/Supplier.java

@@ -0,0 +1,10 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.wot.sugar;
+
+public interface Supplier<T> {
+
+    T get();
+}

pgpainless-wot/src/main/java/org/pgpainless/wot/sugar/package-info.java

@@ -0,0 +1,8 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Syntactic sugar, backported from Java 8.
+ */
+package org.pgpainless.wot.sugar;

pgpainless-wot/src/test/java/org/pgpainless/wot/WebOfTrustTest.java

@@ -19,6 +19,8 @@ public class WebOfTrustTest {
         WebOfTrust wot = new WebOfTrust(store);
         wot.initialize();
 
+        // CHECKSTYLE:OFF
         System.out.println(wot);
+        // CHECKSTYLE:ON
     }
 }

pgpainless-wot/src/testFixtures/java/org/pgpainless/wot/testfixtures/package-info.java

@@ -0,0 +1,8 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Test fixtures for WOT.
+ */
+package org.pgpainless.wot.testfixtures;

wot-dijkstra/src/main/java/org/pgpainless/kotlin_experiments/AJavaClass.java

@@ -11,6 +11,8 @@ public class AJavaClass {
      * Used by {@link org.pgpainless.kotlin_experiments.java_from_kotlin.AccessJavaFromKotlin}.
      */
     public void doSomething() {
+        // CHECKSTYLE:OFF
         System.out.println("Something has been done.");
+        // CHECKSTYLE:ON
     }
 }

wot-dijkstra/src/main/java/org/pgpainless/kotlin_experiments/kotlin_from_java/AccessKotlinFromJava.java

@@ -15,6 +15,8 @@ public class AccessKotlinFromJava {
     public static void main(String[] args) {
         // from src/kotlin/.../
         AKotlinClass kotlin = new AKotlinClass();
+        // CHECKSTYLE:OFF
         kotlin.printToStdout();
+        // CHECKSTYLE:ON
     }
 }

wot-dijkstra/src/main/java/org/pgpainless/kotlin_experiments/kotlin_from_java/package-info.java

@@ -0,0 +1,9 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Demonstration package.
+ * TODO: Delete later.
+ */
+package org.pgpainless.kotlin_experiments.kotlin_from_java;

wot-dijkstra/src/main/java/org/pgpainless/kotlin_experiments/package-info.java

@@ -0,0 +1,9 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Demonstration package.
+ * TODO: Delete later.
+ */
+package org.pgpainless.kotlin_experiments;

wot-dijkstra/src/main/java/org/pgpainless/wot/dijkstra/sq/CertificationSet.java

@@ -121,7 +121,7 @@ public final class CertificationSet {
         StringBuilder sb = new StringBuilder();
         for (Map.Entry<Optional<String>, List<Certification>> entry : certifications.entrySet()) {
             for (Certification certification : entry.getValue()) {
-                sb.append(certification).append("\n");
+                sb.append(certification).append('\n');
             }
         }
         return sb.toString();

wot-dijkstra/src/main/kotlin/org/pgpainless/kotlin_experiments/AKotlinClass.kt

@@ -10,6 +10,8 @@ package org.pgpainless.kotlin_experiments
 class AKotlinClass {
 
     fun printToStdout() {
+        // CHECKSTYLE:OFF
         println("'Hello, World' from Kotlin!")
+        // CHECKSTYLE:ON
     }
 }

wot-dijkstra/src/main/kotlin/org/pgpainless/kotlin_experiments/java_from_kotlin/package-info.java

@@ -0,0 +1,9 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Demonstration package.
+ * TODO: Delete later.
+ */
+package org.pgpainless.kotlin_experiments.java_from_kotlin;

wot-dijkstra/src/main/kotlin/org/pgpainless/kotlin_experiments/package-info.java

@@ -0,0 +1,9 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Demonstration package.
+ * TODO: Delete later.
+ */
+package org.pgpainless.kotlin_experiments;