These environment variables can only handle text strings, as they are external to Python and have to be compatible with other programs and the rest of the system (and even with different operating systems, as Linux, Windows, macOS).

That means that any value read in Python from an environment variable will be a `str`, and any conversion to a different type or any validation has to be done in code.

## Pydantic `Settings` { #pydantic-settings }

                    `response_model`, converting any data as necessary to generate the
                    corresponding JSON. But if the data in the object returned is not
                    valid, that would mean a violation of the contract with the client,
                    so it's an error from the API developer. So, FastAPI will raise an
                    error and return a 500 error code (Internal Server Error).

   *
   * <p>In particular, this map iterates over entries with repeated calls to {@link
   * NavigableMap#lowerEntry}. If a more efficient means of iteration is available, you may wish to
   * override the {@code entryIterator()} method of this class.
   *
   * @since 12.0
   */
  protected class StandardDescendingMap extends Maps.DescendingMap<K, V> {

   *
   * <p>In particular, this map iterates over entries with repeated calls to {@link
   * NavigableMap#lowerEntry}. If a more efficient means of iteration is available, you may wish to
   * override the {@code entryIterator()} method of this class.
   *
   * @since 12.0
   */
  protected class StandardDescendingMap extends Maps.DescendingMap<K, V> {

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

/**
 * A series of tests that support asserting that collections cannot be modified, either through
 * direct or indirect means.
 *
 * @author Robert Konigsberg
 */
@GwtCompatible
@NullMarked
public class UnmodifiableCollectionTests {

  public static void assertMapEntryIsUnmodifiable(Entry<?, ?> entry) {
    try {

         * arg option value is retrieved and instead of returning values[values.length-1] it returns
         * values[0] which means that the original value instead of the overridden one is returned
         * (first wins). With properties values are truely overriden since at the end a map is used
         * to merge which means last wins.
         *
         * TODO Report this behavioral bug with Commons CLI
         */

        futures = null;
        cancel(false);
      } else {
        collectValueFromNonCancelledFuture(index, future);
      }
    } finally {
      /*
       * "null" means: There is no need to access `futures` again during
       * `processCompleted` because we're reading each value during a call to
       * handleOneInputDone.
       */
      decrementCountAndMaybeComplete(null);
    }

    /**
     * Returns all active profiles for the current project build.
     * <p>
     * Active profiles are those that have been explicitly activated through one of the following means:
     * <ul>
     *   <li>Command line activation using the -P flag</li>
     *   <li>Maven settings activation in settings.xml via &lt;activeProfiles&gt;</li>

        assertEquals(0, fileBothDirectoryInfo.getNextEntryOffset());
        assertEquals(0, fileBothDirectoryInfo.getFileIndex());
        // For time fields, 0 in the wire format means Jan 1, 1601, which is negative in Unix epoch
        assertTrue(fileBothDirectoryInfo.createTime() < 0);
        assertTrue(fileBothDirectoryInfo.lastAccess() < 0);
        assertTrue(fileBothDirectoryInfo.lastModified() < 0);

    private transient Object lock = new Object();

    final Supplier<T> delegate;
    final long durationNanos;
    transient volatile @Nullable T value;
    // The special value 0 means "not yet initialized".
    transient volatile long expirationNanos;

    ExpiringMemoizingSupplier(Supplier<T> delegate, long durationNanos) {
      this.delegate = delegate;
      this.durationNanos = durationNanos;