# Templates { #templates }

You can use any template engine you want with **FastAPI**.

A common choice is Jinja2, the same one used by Flask and other tools.

There are utilities to configure it easily that you can use directly in your **FastAPI** application (provided by Starlette).

## Install dependencies { #install-dependencies }

@NullUnmarked
public class ServiceTest extends TestCase {

  /** Assert on the comparison ordering of the State enum since we guarantee it. */
  public void testStateOrdering() {
    // List every valid (direct) state transition.
    assertLessThan(NEW, STARTING);
    assertLessThan(NEW, TERMINATED);

    assertLessThan(STARTING, RUNNING);
    assertLessThan(STARTING, STOPPING);
    assertLessThan(STARTING, FAILED);

        bb.putShort(data2); // data2 (2 bytes, little-endian)
        bb.putShort(data3); // data3 (2 bytes, little-endian)

        // Last 8 bytes (data4) written directly as big-endian bytes
        // Extract individual bytes from leastSig and write them directly
        for (int i = 0; i < 8; i++) {
            result[8 + i] = (byte) (leastSig >>> (56 - i * 8));
        }

        return result;
    }

    /**

import java.util.AbstractSet;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A base implementation of {@link NetworkConnections} for directed networks.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
abstract class AbstractDirectedNetworkConnections<N, E> implements NetworkConnections<N, E> {

/**
 * A generic JUnit test which tests {@code remove} operations on a collection. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@link Map#computeIfAbsent}. Can't be invoked directly; please
 * see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

/**
 * A generic JUnit test which tests {@code replace(K, V, V)} operations on a concurrent map. Can't
 * be invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

 * <p>
 * This interface does not support loading of parent POM(s) from the same backing store, integrators are strongly
 * encouraged to implement {@link ModelSource2} instead of implementing this interface directly.
 *
 * @see ModelSource2
 * @deprecated instead use {@link Source}
 */
@Deprecated

 * method) of a collection. Can't be invoked directly; please see {@link
 * com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

/**
 * A generic JUnit test which tests {@code containsValue()} operations on a map. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
 *
 * @author George van den Driessche
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")