After you have tests, then you can upgrade the **FastAPI** version to a more recent one, and make sure that all your code is working correctly by running your tests.

If everything is working, or after you make the necessary changes, and all your tests are passing, then you can pin your `fastapi` to that new recent version.

## About Starlette { #about-starlette }

```

////

## Recap { #recap }

Apart from all the fancy words used here, the **Dependency Injection** system is quite simple.

Just functions that look the same as the *path operation functions*.

But still, it is very powerful, and allows you to declare arbitrarily deeply nested dependency "graphs" (trees).

/// tip

All this might not seem as useful with these simple examples.

# Copyright 2015 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,

package once

// Singleton contains a pointer to T that must be set once.
// Until the value is set all Get() calls will block.
type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v

    }

    @Override
    public void tearDown(final TestInfo testInfo) throws Exception {
        super.tearDown(testInfo);
        // close runner
        runner.close();
        // delete all files
        runner.clean();
    }

    @Test
    public void test_addIncludeUrlFilter_singleTx() {
        final String sessionId = "session1";
        final String urlPattern = "http://example.com/.*";

I have been avoiding the creation of a new framework for several years. First I tried to solve all the features covered by **FastAPI** using many different frameworks, plug-ins, and tools.

    void testHasMoreElementsBecomeFalse() {
        // Set small amounts so everything fits in one message
        transaction.setParameterBytesWritten(10);
        transaction.setDataBytesWritten(10);

        // First call processes all data
        transaction.nextElement();

        // Should have no more elements since all data fit in first message

	// we also have standard collectors like `GoCollector`.

	// Create all Non-`MetricGroup` collectors here.
	collectors := map[collectorPath]prometheus.Collector{
		debugGoCollectorPath: collectors.NewGoCollector(),
	}

	// Add all `MetricGroup` collectors to the map.
	for _, mg := range allMetricGroups {
		collectors[mg.CollectorPath] = mg
	}

 * {@link UnsupportedOperationException} when they are not implemented. Most implementations should
 * support either all add operations or none of them, all removal operations or none of them, and if
 * and only if all of these are supported, the {@code setCount} methods as well.
 *
 * <p>A multiset uses {@link Object#equals} to determine whether two instances should be considered

				if !isString(v) { // Pre-check value type.
					// All values must be of type string.
					return parsedPolicy, fmt.Errorf("Unknown type %s of conditional field value %s found in POST policy form", reflect.TypeOf(condt).String(), condt)
				}
				// {"acl": "public-read" } is an alternate way to indicate - [ "eq", "$acl", "public-read" ]
				// In this case we will just collapse this into "eq" for all use cases.