Finish Java Kompendium book

Java-Kompendium/kap26/build.gradle

@@ -0,0 +1,25 @@
+plugins {
+    id 'java-library'
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    // Use JUnit Jupiter for testing.
+    testImplementation libs.junit.jupiter
+
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+
+    // This dependency is exported to consumers, that is to say found on their compile classpath.
+    // api libs.commons.math3
+
+    // This dependency is used internally, and not exposed to consumers on their own compile classpath.
+    // implementation libs.guava
+}
+
+tasks.named('test') {
+    // Use JUnit Platform for unit tests.
+    useJUnitPlatform()
+}