# Extra Models { #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

//   "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 {

   *
   * <p>If {@code expectedSize} is exactly the number of entries added to the builder before {@link
   * Builder#build} is called, the builder is likely to perform better than an unsized {@link
   * #builder()} would have.
   *
   * <p>It is not specified if any performance benefits apply if {@code expectedSize} is close to,
   * but not exactly, the number of entries added to the builder.
   *
   * @since 23.1
   */

Notice that the default value is still `None`, so the parameter is still optional.

But now, having `Query(max_length=50)` inside of `Annotated`, we are telling FastAPI that we want it to have **additional validation** for this value, we want it to have maximum 50 characters. 😎

/// tip

	}

	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.

  /*
   * 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.
   *
   * (Perhaps it should also have required that its cause was a RuntimeException. However, that

That's why the current versions are still `0.x.x`, this reflects that each version could potentially have breaking changes. This follows the <a href="https://semver.org/" class="external-link" target="_blank">Semantic Versioning</a> conventions.

You can create production applications with **FastAPI** right now (and you have probably been doing it for some time), you just have to make sure that you use a version that works correctly with the rest of your code.

        }

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

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

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

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`).

        assertEquals(1, stats.getRdmaReads(), "Should have 1 read operation");
        assertEquals(1, stats.getRdmaWrites(), "Should have 1 write operation");
        assertEquals(1, stats.getRdmaSends(), "Should have 1 send operation");
        assertEquals(1, stats.getRdmaReceives(), "Should have 1 receive operation");
        assertEquals(5120, stats.getBytesTransferred(), "Should have transferred 5KB total");