### **4.1 Spark Pi**

Test the Spark installation by running the following compute intensive example, which calculates pi by “throwing darts” at a circle. The program generates points in the unit square ((0,0) to (1,1)) and counts how many points fall within the unit circle within the square. The result approximates pi.

Follow these steps to run the Spark Pi example:

- Login as user **‘spark’**.

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import junit.framework.TestCase;

/**
 * Unit test for IteratorTester.
 *
 * @author Mick Killianey
 */
@GwtCompatible
@SuppressWarnings("serial") // No serialization is used in this test
public class IteratorTesterTest extends TestCase {

   *
   * TODO: make this inline once this is fixed: https://github.com/oracle/graal/issues/3466
   */
  fun execute(
    name: String,
    delayNanos: Long = 0L,
    cancelable: Boolean = true,
    block: () -> Unit,
  ) {
    schedule(
      object : Task(name, cancelable) {
        override fun runOnce(): Long {
          block()
          return -1L
        }
      },
      delayNanos,
    )
  }

import org.codelibs.fess.exception.InvalidQueryException;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.lastaflute.core.message.UserMessages;
import org.opensearch.common.unit.Fuzziness;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.search.sort.SortOrder;

public class TermQueryCommand extends QueryCommand {

import java.util.Comparator;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.SortedSet;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit tests for {@code TreeMultimap} with explicit comparators.
 *
 * @author Jared Levy
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class TreeMultimapExplicitTest extends TestCase {

import static org.junit.Assert.assertThrows;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;
import java.util.Map;
import junit.framework.TestCase;

/**
 * Unit tests of {@link TypeResolver}.
 *
 * @author Ben Yu
 */
@AndroidIncompatible // lots of failures, possibly some related to bad equals() implementations?
public class TypeResolverTest extends TestCase {

import static org.junit.Assert.assertThrows;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;
import java.util.Map;
import junit.framework.TestCase;

/**
 * Unit tests of {@link TypeResolver}.
 *
 * @author Ben Yu
 */
@AndroidIncompatible // lots of failures, possibly some related to bad equals() implementations?
public class TypeResolverTest extends TestCase {

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import junit.framework.TestCase;

/**
 * Unit test for IteratorTester.
 *
 * @author Mick Killianey
 */
@GwtCompatible
@SuppressWarnings("serial") // No serialization is used in this test
public class IteratorTesterTest extends TestCase {

import java.util.Set;
import java.util.SortedSet;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@link TreeMultiset}.
 *
 * @author Neal Kanodia
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class TreeMultisetTest extends TestCase {

  @J2ktIncompatible

import com.google.common.testing.SerializableTester;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Random;
import junit.framework.TestCase;

/**
 * Unit test for {@link UnsignedBytes}.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 */
public class UnsignedBytesTest extends TestCase {
  private static final byte LEAST = 0;