Import `BaseSettings` from Pydantic and create a sub-class, very much like with a Pydantic model.

The same way as with Pydantic models, you declare class attributes with type annotations, and possibly default values.

You can use all the same validation features and tools you use for Pydantic models, like different data types and additional validations with `Field()`.

//// tab | Pydantic v2

```Python hl_lines="2  5-8  11"

	if err = saveServerConfig(ctx, objectAPI, cfg); err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

	// freshly retrieve the config so that default values are loaded for reset config
	if cfg, err = getValidConfig(objectAPI); err != nil {
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
		return
	}

	dynamic := config.SubSystemsDynamic.Contains(subSys)

// input DN, as LDAP equality is not a simple Golang string equality. However,
// we assume the value returned by the LDAP server is canonical. Additionally,
// the attribute type names in the DN are lower-cased.
//
// Return values:
//
// If the DN is found, the normalized (string) value and any requested
// attributes are returned and error is nil.
//
// If the DN is not found, a nil result and error are returned.
//

  }

  /**
   * Returns an equivalence that delegates to {@link Object#equals} and {@link Object#hashCode}.
   * {@link Equivalence#equivalent} returns {@code true} if both values are null, or if neither
   * value is null and {@link Object#equals} returns {@code true}. {@link Equivalence#hash} returns
   * {@code 0} if passed a null value.
   *
   * @since 13.0

        session.setScopeManager(getScopeManager());
    }

    /**
     * Creates a new Maven-like repository system session by initializing the session with values typical for
     * Maven-based resolution. In more detail, this method configures settings relevant for the processing of dependency

            n = in.read( b, off + i, len - i );
            if (n <= 0) {
                break;
            }
            i += n;
        }

        return i;
    }

    /* state values
     * 0 - not connected
     * 1 - connecting
     * 2 - run connected
     * 3 - connected
     * 4 - error
     */
    int state = 0;

    String name = "Transport" + id++;
    Thread thread;

  optional k8s.io.api.core.v1.ObjectReference related = 9;

  // note is a human-readable description of the status of this operation.
  // Maximal length of the note is 1kB, but libraries should be prepared to
  // handle values up to 64kB.
  // +optional
  optional string note = 10;

  // type is the type of this event (Normal, Warning), new types could be added in the future.
  // It is machine-readable.
  // +optional

                    // Note that Firefox is fine with a sort function returning any positive or negative number, but Chrome 
                    // requires 1 or -1 specifically and ignores higher or lower values.  This sort ought to remain consistent
                    // with the sort used by AbstractAcceptedApiChangesMaintenanceTask.
                    result.acceptedApiChanges.sort((a, b) => { 

    public boolean available() {
        return available;
    }

    @Override
    public void destroy() {
        available = false;
        for (final ComponentHolder<?> componentHolder : singletonMap.values()) {
            try {
                componentHolder.destroy();
            } catch (final Exception e) {
                logger.warn("Failed to destroy " + componentHolder.get(), e);
            }
        }
    }

    <name>join</name>
    <function-class>org.codelibs.fess.taglib.FessFunctions</function-class>
    <function-signature>java.lang.String join(java.lang.Object)</function-signature>
    <example>${fe:join(values)}</example>
  </function>

  <function>
    <description>
      Returns a string resulting from replacing in an input string all occurrences
      of a "before" string into an "after" substring.