// policy for the STS credential. The policy mapping can be updated by the
// administrator.
//
// - from `Subject.CommonName` field from the STS request for
// AssumeRoleWithCertificate. In this case, the policy for the STS credential
// has the same name as the value of this field.
//
// - from special JWT claim from STS request for AssumeRoleWithOIDC API (when

	if errCode != ErrUnsignedHeaders {
		t.Fatalf("Expected the APIErrorCode to %d, but got %d", ErrUnsignedHeaders, errCode)
	}

	// case where the list of signed headers doesn't contain the host field.
	signedHeaders = signedHeaders[2:5]
	// expected to fail with `ErrUnsignedHeaders`.
	_, errCode = extractSignedHeaders(signedHeaders, r)
	if errCode != ErrUnsignedHeaders {

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"
{!> ../../docs_src/settings/tutorial001.py!}
```

////

//// tab | Pydantic v1

/// info

🗄 `BaseSettings` ⚪️➡️ Pydantic & ✍ 🎧-🎓, 📶 🌅 💖 ⏮️ Pydantic 🏷.

🎏 🌌 ⏮️ Pydantic 🏷, 👆 📣 🎓 🔢 ⏮️ 🆎 ✍, & 🎲 🔢 💲.

👆 💪 ⚙️ 🌐 🎏 🔬 ⚒ & 🧰 👆 ⚙️ Pydantic 🏷, 💖 🎏 📊 🆎 & 🌖 🔬 ⏮️ `Field()`.

```Python hl_lines="2  5-8  11"
{!../../docs_src/settings/tutorial001.py!}
```

/// tip

🚥 👆 💚 🕳 ⏩ 📁 & 📋, 🚫 ⚙️ 👉 🖼, ⚙️ 🏁 1️⃣ 🔛.

///

  /** The parts of the domain name, converted to lower case. */
  private final ImmutableList<String> parts;

  /**
   * Cached value of #publicSuffixIndex(). Do not use directly.
   *
   * <p>Since this field isn't {@code volatile}, if an instance of this class is shared across
   * threads before it is initialized, then each thread is likely to compute their own copy of the
   * value.
   */
  @SuppressWarnings("Immutable")

    static final byte SMB_COM_NT_TRANSACT_SECONDARY = (byte)0xA1;
    static final byte SMB_COM_NT_CREATE_ANDX     = (byte)0xA2;

    /*
     * Some fields specify the offset from the beginning of the header. This
     * field should be used for calculating that. This would likely be zero
     * but an implemantation that encorporates the transport header(for

func (c *Client) dumpHTTP(req *http.Request, resp *http.Response) {
	// Starts http dump.
	_, err := fmt.Fprintln(c.TraceOutput, "---------START-HTTP---------")
	if err != nil {
		return
	}

	// Filter out Signature field from Authorization header.
	origAuth := req.Header.Get("Authorization")
	if origAuth != "" {
		req.Header.Set("Authorization", "**REDACTED**")
	}

	// Only display request header.

     * purposes, the "count" field, tracking the number of elements, serves as that volatile
     * variable ensuring visibility. This is convenient because this field needs to be read in many
     * read operations anyway:
     *
     * - All (unsynchronized) read operations must first read the "count" field, and should not look
     * at table entries if it is 0.
     *

	}

	var isLocal bool
	var host string
	u, err := url.Parse(arg)
	if err == nil && u.Host != "" {
		// URL style of endpoint.
		// Valid URL style endpoint is
		// - Scheme field must contain "http" or "https"
		// - All field should be empty except Host and Path.
		if !((u.Scheme == "http" || u.Scheme == "https") &&
			u.User == nil && u.Opaque == "" && !u.ForceQuery && u.RawQuery == "" && u.Fragment == "") {

   *   challenge. In this case the request URL may be different than the initial request URL.
   *
   * Use the `request` of the [networkResponse] field to get the wire-level request that was
   * transmitted. In the case of follow-ups and redirects, also look at the `request` of the
   * [priorResponse] objects, which have its own [priorResponse].
   */