That means that, clients using your API don't have to check if the value exists or not, they can **assume the field will always be there**, but just that in some cases it will have the default value of `None`.

The way to describe this in OpenAPI, is to mark that field as **required**, because it will always be there.

Because of that, the JSON Schema for a model can be different depending on if it's used for **input or output**:

### Bigger Errors - Crashes

Nevertheless, there might be cases where we write some code that **crashes the entire application** making Uvicorn and Python crash. 💥

And still, you would probably not want the application to stay dead because there was an error in one place, you probably want it to **continue running** at least for the *path operations* that are not broken.

# TFCI_BAZEL_TARGET_SELECTING_CONFIG_PREFIX. "Available" means there is
# an entry in tensorflow/.bazelrc for build:rbe_TFCI_BAZEL_TARGET...
#                                           ^^^^
# This env is only valid when RBE is available on the selected platform, since
# it enables a derived --config setting.  If RBE is not available (i.e. there
# is no --config setting), bazel would fail and quit. This script does a quick

      }
    },
    /**
     * Return {@code ~insertionIndex}, where {@code insertionIndex} is defined as the point at which
     * the key would be inserted into the list: the index of the next higher element in the list, or
     * {@code list.size()} if there is no such element.
     *
     * <p>Note that the return value will be {@code >= 0} if and only if there is an element of the
     * list that compares as equal to the key.
     *

        }
        draining = false;
        Java8Compatibility.clear(byteBuffer);
      }

      while (true) {
        // We call encode until there is no more input. The last call to encode will have endOfInput
        // == true. Then there is a final call to flush.
        CoderResult result;
        if (doneFlushing) {
          result = CoderResult.UNDERFLOW;
        } else if (doneEncoding) {

        }
        draining = false;
        Java8Compatibility.clear(byteBuffer);
      }

      while (true) {
        // We call encode until there is no more input. The last call to encode will have endOfInput
        // == true. Then there is a final call to flush.
        CoderResult result;
        if (doneFlushing) {
          result = CoderResult.UNDERFLOW;
        } else if (doneEncoding) {

# OpenAPI Webhooks

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps

      }
    },
    /**
     * Return {@code ~insertionIndex}, where {@code insertionIndex} is defined as the point at which
     * the key would be inserted into the list: the index of the next higher element in the list, or
     * {@code list.size()} if there is no such element.
     *
     * <p>Note that the return value will be {@code >= 0} if and only if there is an element of the
     * list that compares as equal to the key.
     *

        "Throwable from other thread: "
            + (throwable == null ? null : Throwables.getStackTraceAsString(throwable)),
        throwableFromOtherThread.get());
  }

  /**
   * Test for a bug where threads weren't getting signaled when shutdown was called, only when tasks
   * completed.
   */
  public void testDirectExecutorService_awaitTermination_missedSignal() {

   * needed.
   *
   * A single spinlock ("busy") is used for initializing and
   * resizing the table, as well as populating slots with new Cells.
   * There is no need for a blocking lock; when the lock is not
   * available, threads try other slots (or the base).  During these
   * retries, there is increased contention and reduced locality,
   * which is still better than alternatives.
   *
   * Per-thread hash codes are initialized to random values.