code: package org.gridkit.jvmtool.stacktrace;
  
  import java.io.IOException;
  import java.lang.management.ManagementFactory;
  
  import org.junit.Assert;
  import org.junit.Test;
  
  public class InProcessSamplerCheck {
  
      @Test
      public void testLocalAccess() throws IOException {
          ThreadDumpSampler sampler = new ThreadDumpSampler();
          sampler.connect(ManagementFactory.getThreadMXBean());
          sampler.collect(new StackTraceWriter() {
  
              @Override
              public void write(ThreadSnapshot snap) throws IOException {
                  Assert.assertTrue(snap.counters().getValue(ThreadCounters.ALLOCATED_BYTES) >= 0);
              }
  
              @Override
              public void close() {
              }
          });
      }
  
  }
  