{* ../../docs_src/response_directly/tutorial001_py310.py hl[5:6,20:21] *}

/// note | Technical Details

You could also use `from starlette.responses import JSONResponse`.

**FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette.

///

## Returning a custom `Response` { #returning-a-custom-response }

keystone:
  - url: https://fastapicloud.com
    title: FastAPI Cloud. By the same team behind FastAPI. You code. We Cloud.
    img: https://fastapi.tiangolo.com/img/sponsors/fastapicloud.png
gold:
  - url: https://blockbee.io?ref=fastapi
    title: BlockBee Cryptocurrency Payment Gateway
    img: https://fastapi.tiangolo.com/img/sponsors/blockbee.png
  - url: https://github.com/scalar/scalar/?utm_source=fastapi&utm_medium=website&utm_campaign=main-badge

	if err != nil {
		t.Fatalf("Failed to get a new credential: %v", err)
	}
	testCases := []struct {
		cred           Credentials
		ccred          Credentials
		expectedResult bool
	}{
		// Same Credentialss.
		{cred, cred, true},
		// Empty credentials to compare.
		{cred, Credentials{}, false},
		// Empty credentials.
		{Credentials{}, cred, false},
		// Two different credentialss

 * <p>The collections created by {@link #createCollection()} may or may not allow duplicates. If the
 * collection, such as a {@link Set}, does not support duplicates, an added key-value pair will
 * replace an existing pair with the same key and value, if such a pair is present. With collections
 * like {@link List} that allow duplicates, the collection will keep the existing key-value pairs
 * while adding a new pair.
 *

   * the segment.
   */
  final int segmentMask;

  /**
   * Shift value for indexing within segments. Helps prevent entries that end up in the same segment
   * from also ending up in the same bucket.
   */
  final int segmentShift;

  /** The segments, each of which is a specialized hash table. */
  final Segment<K, V>[] segments;

  /** The concurrency level. */

   * problematic AtomicReferenceFieldUpdaterAtomicHelper code path. However, the same problem *does*
   * matter with AggregateFutureState, which does not have an Unsafe-based helper.
   *
   * This same problem is one of the reasons for us to likewise use package-private for the fields
   * in Waiter.
   */

  /**

 * {@link #at}, {@link #set}, {@link #toArray}, {@link #rowKeyList}, and {@link #columnKeyList}
 * methods for more details.
 *
 * <p>Note that this implementation is not synchronized. If multiple threads access the same cell of
 * an {@code ArrayTable} concurrently and one of the threads modifies its value, there is no
 * guarantee that the new value will be fully visible to the other threads. To guarantee that

import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Test;

/**
 * Automatically runs sanity checks against top level classes in the same package of the test that
 * extends {@code AbstractPackageSanityTests}. Currently sanity checks include {@link
 * NullPointerTester}, {@link EqualsTester} and {@link SerializableTester}. For example:
 *
 * <pre>

    assertThat(longIterator.hasNext()).isFalse();
  }

  public void testCopyOf_array_empty() {
    /*
     * We don't guarantee the same-as property, so we aren't obligated to test it. However, it's
     * useful in testing - when two things are the same then one can't have bugs the other doesn't.
     */
    assertThat(ImmutableLongArray.copyOf(new long[0])).isSameInstanceAs(ImmutableLongArray.of());
  }

	errLifecycleNoRule       = Errorf("Lifecycle configuration should have at least one rule")
	errLifecycleDuplicateID  = Errorf("Rule ID must be unique. Found same ID for more than one rule")
	errXMLNotWellFormed      = Errorf("The XML you provided was not well-formed or did not validate against our published schema")