# Background Tasks { #background-tasks }

You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

   * this graph.
   *
   * <p>This is equal to the union of {@link #predecessors(Object)} and {@link #successors(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *

   * this graph.
   *
   * <p>This is equal to the union of {@link #predecessors(Object)} and {@link #successors(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code
   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *

import okio.Options
import okio.Source
import okio.Timeout
import okio.buffer

/**
 * Reads a stream of [RFC 2046][rfc_2046] multipart body parts. Callers read parts one-at-a-time
 * until [nextPart] returns null. After calling [nextPart] any preceding parts should not be read.
 *
 * Typical use loops over the parts in sequence:
 *
 * ```kotlin
 * val response: Response = call.execute()

   *
   * <p>If {@code !range.contains(k)}, {@link #get(Comparable) get(k)} will return the same result
   * before and after a call to {@code remove(range)}. If {@code range.contains(k)}, then after a
   * call to {@code remove(range)}, {@code get(k)} will return {@code null}.
   */
  void remove(Range<K> range);

  /**

   *     operation
   */
  void add(Range<C> range);

  /**
   * Removes the specified range from this {@code RangeSet} (optional operation). After this
   * operation, if {@code range.contains(c)}, {@code this.contains(c)} will return {@code false}.
   *
   * <p>If {@code range} is empty, this is a no-op.
   *

    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutIfAbsent_nullValueUnsupportedAndKeyAbsent() {

    assertEquals(
        "multiset.remove(present, 2) didn't return the old count",
        1,
        getMultiset().remove(e0(), 2));
    assertFalse(
        "multiset contains present after multiset.remove(present, 2)",
        getMultiset().contains(e0()));
    assertEquals(0, getMultiset().count(e0()));
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)

    assertEquals(
        "multiset.remove(present, 2) didn't return the old count",
        1,
        getMultiset().remove(e0(), 2));
    assertFalse(
        "multiset contains present after multiset.remove(present, 2)",
        getMultiset().contains(e0()));
    assertEquals(0, getMultiset().count(e0()));
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)

import java.util.Arrays;

import jcifs.internal.smb2.lease.Smb2LeaseKey;

/**
 * Information about a durable or persistent SMB handle.
 * This class holds all the necessary information to reconnect
 * a handle after network failures or server reboots.
 */
public class HandleInfo implements Serializable {

    private static final long serialVersionUID = 1L;

    /**