title="also called marshalling, conversion">serialization</dfn>" which is taking data from the code (Python) and converting it into something that can be sent through the network. For example, converting an object containing data from a database into a JSON object. Converting `datetime` objects into strings, etc.

Another big feature needed by APIs is data validation, making sure that the data is valid, given certain parameters. For example, that some field is an `int`, and not some random...

    }

    @Override
    public boolean equals(@Nullable Object object) {
      if (object == this) {
        return true;
      }
      if (object instanceof DoubleArrayAsList) {
        DoubleArrayAsList that = (DoubleArrayAsList) object;
        int size = size();
        if (that.size() != size) {
          return false;
        }

	},
	ErrObjectLockInvalidHeaders: {
		Code:           "InvalidRequest",
		Description:    "x-amz-object-lock-retain-until-date and x-amz-object-lock-mode must both be supplied",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrObjectRestoreAlreadyInProgress: {
		Code:           "RestoreAlreadyInProgress",
		Description:    "Object restore is already in progress",
		HTTPStatusCode: http.StatusConflict,
	},

 * the License.
 */

package com.google.common.base;

import static com.google.common.base.Preconditions.checkNotNull;
import static java.util.Objects.requireNonNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;

import org.eclipse.aether.version.Version;
import org.eclipse.aether.version.VersionRange;
import org.eclipse.aether.version.VersionScheme;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static java.util.Objects.requireNonNull;

/**
 * @since 3.3.0
 */
@Named
@Singleton
public class DefaultRepositorySystemSessionFactory implements RepositorySystemSessionFactory {

 * the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.collect.Sets.newConcurrentHashSet;
import static java.util.Objects.requireNonNull;
import static java.util.concurrent.atomic.AtomicIntegerFieldUpdater.newUpdater;
import static java.util.concurrent.atomic.AtomicReferenceFieldUpdater.newUpdater;

        }
      };

  enum NullListener implements RemovalListener<Object, Object> {
    INSTANCE;

    @Override
    public void onRemoval(RemovalNotification<Object, Object> notification) {}
  }

  enum OneWeigher implements Weigher<Object, Object> {
    INSTANCE;

    @Override
    public int weigh(Object key, Object value) {
      return 1;
    }
  }

   *
   * @throws UnsupportedOperationException always
   * @deprecated <b>Pass keys of type {@code Comparable} to use {@link
   *     ImmutableSortedMap#of(Comparable, Object, Comparable, Object, Comparable, Object,
   *     Comparable, Object, Comparable, Object)}.</b>
   */
  @DoNotCall("Pass keys of type Comparable")
  @Deprecated
  public static <K, V> ImmutableSortedMap<K, V> of(

      queue[i] = null;
    }
    size = 0;
  }

  @Override
  @J2ktIncompatible // Incompatible return type change. Use inherited (unoptimized) implementation
  public Object[] toArray() {
    Object[] copyTo = new Object[size];
    arraycopy(queue, 0, copyTo, 0, size);
    return copyTo;
  }

  /**
   * Returns the comparator used to order the elements in this queue. Obeys the general contract of

  /**
   * For <a href="https://tools.ietf.org/html/rfc7515">JWS or JWE objects using the Compact
   * Serialization</a>.
   *
   * @since 27.1
   */
  public static final MediaType JOSE = createConstant(APPLICATION_TYPE, "jose");

  /**
   * For <a href="https://tools.ietf.org/html/rfc7515">JWS or JWE objects using the JSON
   * Serialization</a>.
   *
   * @since 27.1
   */