import com.google.common.collect.testing.features.CollectionSize;
import java.lang.reflect.Method;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests add operations on a set. Can't be invoked directly; please see
 * {@link com.google.common.collect.testing.SetTestSuiteBuilder}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible

import com.google.common.collect.testing.features.CollectionSize;
import java.util.NoSuchElementException;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code remove()} operations on a queue. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Jared Levy
 */
@GwtCompatible

    Feature<?>[] presentFeatures;
    Feature<?>[] absentFeatures;
    try {
      presentFeatures = (Feature<?>[]) annotationClass.getMethod("value").invoke(testerAnnotation);
      absentFeatures = (Feature<?>[]) annotationClass.getMethod("absent").invoke(testerAnnotation);
    } catch (Exception e) {
      throw new IllegalArgumentException("Error extracting features from tester annotation.", e);
    }

import java.util.concurrent.ConcurrentMap;
import org.jspecify.annotations.NullMarked;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code putIfAbsent} operations on a concurrent map. Can't be
 * invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

      this.map = map;
      this.setUpRan = setUpRan;
    }

    @Override
    public Object invoke(Object target, Method method, Object[] args) throws Throwable {
      assertTrue("setUp should have run", setUpRan.get());
      try {
        return method.invoke(map, args);
      } catch (InvocationTargetException e) {
        throw e.getCause();
      } catch (IllegalAccessException e) {

     * interceptors.
     *
     * ```kotlin
     * val interceptor = Interceptor { chain: Interceptor.Chain ->
     *     chain.proceed(chain.request())
     * }
     * ```
     */
    inline operator fun invoke(crossinline block: (chain: Chain) -> Response): Interceptor = Interceptor { block(it) }
  }

  interface Chain {
    fun request(): Request

    @Throws(IOException::class)
    fun proceed(request: Request): Response

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code listIterator} operations on a list. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
 *
 * @author Chris Povirk
 * @author Kevin Bourrillion
 */
@GwtCompatible

import java.util.Map;
import java.util.Map.Entry;
import junit.framework.AssertionFailedError;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#computeIfPresent}. Can't be invoked directly; please
 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

  }

  @J2ktIncompatible
  @GwtIncompatible // java.lang.reflect
  private static Object invokeAccessibleNonThrowingMethod(
      Method method, Object receiver, Object... params) {
    try {
      return method.invoke(receiver, params);
    } catch (IllegalAccessException e) {
      throw new RuntimeException(e);
    } catch (InvocationTargetException e) {
      throw propagate(e.getCause());
    }
  }

En este caso, es el `str`:

```Python
"{$callback_url}/invoices/{$request.body.id}"
```

Entonces, si el usuario de tu API (el desarrollador externo) envía un request a *tu API* a:

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

con un JSON body de:

```JSON
{
    "id": "2expen51ve",