A DESCRIPTION OF THE PROBLEM :
java.lang.NullPointerException
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitApply(Flow.java:1233)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1634)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.visitExec(TreeScanner.java:213)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1452)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:57)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitBlock(Flow.java:995)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1020)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitForeachLoop(Flow.java:1034)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCEnhancedForLoop.accept(JCTree.java:1160)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:57)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitBlock(Flow.java:995)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1020)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitMethodDef(Flow.java:962)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:866)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.visitClassDef(Flow.java:925)
at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:774)
at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:396)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.analyzeTree(Flow.java:1325)
at jdk.compiler/com.sun.tools.javac.comp.Flow$FlowAnalyzer.analyzeTree(Flow.java:1315)
at jdk.compiler/com.sun.tools.javac.comp.Flow.analyzeTree(Flow.java:216)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1393)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1367)
at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:965)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.lambda$doCall$0(JavacTaskImpl.java:100)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.handleExceptions(JavacTaskImpl.java:142)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:96)
at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:90)
at org.codehaus.plexus.compiler.javac.JavaxToolsCompiler.compileInProcess(JavaxToolsCompiler.java:126)
at org.codehaus.plexus.compiler.javac.JavacCompiler.performCompile(JavacCompiler.java:174)
at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:1075)
at org.apache.maven.plugin.compiler.CompilerMojo.execute(CompilerMojo.java:168)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:154)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:146)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:956)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:290)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:194)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)