Dat betekent dat **elke waarde** die in Python uit een omgevingsvariabele wordt gelezen **een `str` zal zijn** en dat elke conversie naar een ander type of elke validatie in de code moet worden uitgevoerd.

    * JSON.
    * Pad parameters.
    * Query parameters.
    * Cookies.
    * Headers.
    * Formulieren.
    * Bestanden.
* <abbr title="ook bekend als: serialisatie, parsing, marshalling">Conversie</abbr> van uitvoergegevens: converstie van Python-data en -types naar netwerkgegevens (zoals JSON):

    .build();
```

Client Authentication
---------------------

The above scenario is representative of most TLS set ups: the client uses certificates to validate
the identity of a server. The converse is also possible. Here we create a server that authenticates
a client and a client that authenticates a server.

```java
// Create the root for client and server to trust. We could also use different roots for each!

  /**
   * The lifecycle states of a service.
   *
   * <p>The ordering of the {@link State} enum is defined such that if there is a state transition
   * from {@code A -> B} then {@code A.compareTo(B) < 0}. N.B. The converse is not true, i.e. if
   * {@code A.compareTo(B) < 0} then there is <b>not</b> guaranteed to be a valid state transition
   * {@code A -> B}.
   *
   * @since 9.0 (in 1.0 as {@code com.google.common.base.Service.State})

            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]
}
```

car le paramètre de chemin `item_id` possède comme valeur `"foo"`, qui ne peut pas être convertie en entier (`int`).

La même erreur se produira si vous passez un nombre flottant (`float`) et non un entier, comme ici

  /**
   * The lifecycle states of a service.
   *
   * <p>The ordering of the {@link State} enum is defined such that if there is a state transition
   * from {@code A -> B} then {@code A.compareTo(B) < 0}. N.B. The converse is not true, i.e. if
   * {@code A.compareTo(B) < 0} then there is <b>not</b> guaranteed to be a valid state transition
   * {@code A -> B}.
   *
   * @since 9.0 (in 1.0 as {@code com.google.common.base.Service.State})

        return Optional.ofNullable(location);
    }

    /**
     * Returns the path type associated to the given {@code javax.tool} location.
     * This method is the converse of {@link #location()}.
     *
     * @param location identification of a path in the {@code javax.tool} API
     * @return Java path type associated to the given location
     */

   *       contained by the latter range)
   * </ul>
   *
   * <p>Note that if {@code a.encloses(b)}, then {@code b.contains(v)} implies {@code
   * a.contains(v)}, but as the last two examples illustrate, the converse is not always true.
   *
   * <p>Being reflexive, antisymmetric and transitive, the {@code encloses} relation defines a
   * <i>partial order</i> over ranges. There exists a unique {@linkplain Range#all maximal} range

   *       contained by the latter range)
   * </ul>
   *
   * <p>Note that if {@code a.encloses(b)}, then {@code b.contains(v)} implies {@code
   * a.contains(v)}, but as the last two examples illustrate, the converse is not always true.
   *
   * <p>Being reflexive, antisymmetric and transitive, the {@code encloses} relation defines a
   * <i>partial order</i> over ranges. There exists a unique {@linkplain Range#all maximal} range

     * int.
     */
    checkNonNegative("a", a);
    checkNonNegative("b", b);
    if (a == 0) {
      // 0 % b == 0, so b divides a, but the converse doesn't hold.
      // BigInteger.gcd is consistent with this decision.
      return b;
    } else if (b == 0) {
      return a; // similar logic
    }
    /*