#### Including layers into configuration models

Layers are included into configuration defined using `config` element under element `layers`, e.g.

[source,xml]
----
<config xmlns="urn:jboss:galleon:config:1.0" model="model1" name="name1">
    <layers>
        <include name="layer1"/>
        <include name="layer2"/>
    </layers>
    <!-- the rest of the configuration -->
</config>
----

Let's suppose the configuration above belongs to a feature-pack `prod1`. And `prod1` also predefined another layer - `layer3`, which is not included into the default configuration `model1:name1`. Here is how `layer3` can be added to the final configuration by a user:

[source,xml]
----
<installation xmlns="urn:jboss:galleon:provisioning:2.0">
    <feature-pack location="prod1@maven(org.jboss.universe:community-universe):1#1.0.0.Final"/>
    <config xmlns="urn:jboss:galleon:config:1.0" model="model1" name="name1">
        <layers>
            <include name="layer3"/>
        </layers>
        <!-- the rest of the configuration -->
    </config>
</installation>
----

The resulting `model1:name1` configuration now will include `layer1`, `layer2` and `layer3` and they will be included into the configuration in exactly that order.

IMPORTANT: The statement above is valid only if the mentioned layers don't depend on each other and/or other layers.

