# Extra Models

Continuing with the previous example, it will be common to have more than one related model.

This is especially the case for user models, because:

* The **input model** needs to be able to have a password.
* The **output model** should not have a password.
* The **database model** would probably need to have a hashed password.

/// danger

Never store user's plaintext passwords. Always store a "secure hash" that you can then verify.

	if sepIndex == -1 {
		return nil, fmt.Errorf("'%s' does not have a valid range value", rangeString)
	}

	offsetBeginString := byteRangeString[:sepIndex]
	offsetBegin := int64(-1)
	// Convert offsetBeginString only if its not empty.
	if len(offsetBeginString) > 0 {
		if offsetBeginString[0] == '+' {
			return nil, fmt.Errorf("Byte position ('%s') must not have a sign", offsetBeginString)

        }

        int have = this.handle.sendrecv(buf, off, length, inB, getMaxRecv());

        int fraglen = Encdec.dec_uint16le(inB, 8);
        if ( fraglen > getMaxRecv() ) {
            throw new IOException("Unexpected fragment length: " + fraglen);
        }

        while ( have < fraglen ) {
            int r = this.handle.recv(inB, have, fraglen - have);
            if ( r == 0 ) {

// ClusterTrustBundles by default.  Users who only have namespace-level access
// to a cluster can read ClusterTrustBundles by impersonating a serviceaccount
// that they have access to.
//
// It can be optionally associated with a particular assigner, in which case it
// contains one valid set of trust anchors for that signer. Signers may have

	}

	for _, count := range vidMap {
		// do we have enough common versions
		// that have enough quorum to satisfy
		// the etag.
		if count >= quorum {
			return etags
		}
	}

	return make([]string, len(partsMetadata))
}

// Extracts list of times from FileInfo slice and returns, skips
// slice elements which have errors.

# Security - First Steps

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

Using these ideas, JWT can be used for way more sophisticated scenarios.

In those cases, several of those entities could have the same ID, let's say `foo` (a user `foo`, a car `foo`, and a blog post `foo`).

//   "format": "XXXXX",
//   "XXXXX": {
//
//   }
// }
// Here "XXXXX" depends on the backend, currently we have "fs" and "xl" implementations.
// formatMetaV1 should be inherited by backend format structs. Please look at format-fs.go
// and format-xl.go for details.

// Ideally we will never have a situation where we will have to change the
// fields of this struct and deal with related migration.
type formatMetaV1 struct {

<blockquote markdown="1">

**FastAPI** wouldn't exist if not for the previous work of others.

There have been many tools created before that have helped inspire its creation.

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.

  /*
   * Ideally, this class would have exposed only constructors that require a non-null cause. See
   * https://github.com/jspecify/jspecify-reference-checker/blob/61aafa4ae52594830cfc2d61c8b113009dbdb045/src/main/java/com/google/jspecify/nullness/NullSpecTransfer.java#L789
   * and https://github.com/jspecify/jspecify/issues/490.
   *
   * (That would also have ensured that its cause was always an Error, rather than possibly another