Add loadFromPOM magic test

jjava/src/test/java/org/dflib/jjava/jupyter/kernel/KernelMagicIT.java

@@ -8,7 +8,7 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-public class KernelMagicIT extends ContainerizedKernelCase {
+class KernelMagicIT extends ContainerizedKernelCase {
 
     @Test
     void jars() throws Exception {
@@ -68,4 +68,18 @@ void load() throws Exception {
         assertThat(snippetResult.getStderr(), not(containsString("|")));
         assertThat(snippetResult.getStdout(), containsString("pong!"));
     }
+
+    @Test
+    void loadFromPOM() throws Exception {
+        String pom = CONTAINER_RESOURCES + "/test-pom.xml";
+        String snippet = String.join("\n",
+                "%loadFromPOM " + pom,
+                "import jakarta.annotation.Nullable;",
+                "Nullable.class.getName()"
+        );
+        Container.ExecResult snippetResult = executeInKernel(snippet);
+
+        assertThat(snippetResult.getStderr(), not(containsString("|")));
+        assertThat(snippetResult.getStdout(), containsString("jakarta.annotation.Nullable"));
+    }
 }

jjava/src/test/resources/test-pom.xml

@@ -0,0 +1,15 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.dflib.jjava</groupId>
+    <artifactId>jjava-test</artifactId>
+    <version>1.0</version>
+
+    <dependencies>
+        <dependency>
+            <groupId>jakarta.annotation</groupId>
+            <artifactId>jakarta.annotation-api</artifactId>
+            <version>3.0.0</version>
+        </dependency>
+    </dependencies>
+</project>