Example failure of slice boundary

TestSliceBoundary.java

import static org.junit.Assert.assertEquals;

import org.apache.arrow.memory.BufferAllocator;
import org.apache.arrow.memory.RootAllocator;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

import io.netty.buffer.ArrowBuf;

public class TestSliceBoundary {

  @Rule
  public ExpectedException thrown = ExpectedException.none();

  @Test
  public void ensureOversizedSliceFail() {
    try (BufferAllocator allocator = new RootAllocator(128);
    ArrowBuf buf = allocator.buffer(2);
        ){
      assertEquals(2, buf.capacity());
      
      thrown.expect(IllegalArgumentException.class);
      
      // should fail but doesn't.
      buf.slice(0, 3);
    }

  }
}