feat: add support for Schema.xml property

Author: itsjavi

src/Spec/v3/Schema.php

@@ -161,7 +161,7 @@ class Schema extends AbstractObject
    * describe the XML representation of this property.
    *
    * @see https://swagger.io/specification/#xmlObject
-   * @var array
+   * @var Xml
    */
     public $xml;
 

src/Spec/v3/Xml.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace erasys\OpenApi\Spec\v3;
+
+/**
+ * A metadata object that allows for more fine-tuned XML model definitions.
+ * When using arrays, XML element names are not inferred (for singular/plural forms)
+ * and the name property SHOULD be used to add that information.
+ *
+ * See examples for expected behavior.
+ *
+ * @see https://swagger.io/specification/#xmlObject
+ */
+class Xml extends AbstractObject
+{
+    /**
+     * Replaces the name of the element/attribute used for the described schema property.
+     * When defined within items, it will affect the name of the individual XML elements within the list.
+     * When defined alongside type being array (outside the items),
+     * it will affect the wrapping element and only if wrapped is true.
+     *
+     * If wrapped is false, it will be ignored.
+     *
+     * @var string
+     */
+    public $name;
+
+    /**
+     * The URI of the namespace definition. Value MUST be in the form of an absolute URI.
+     *
+     * @var string
+     */
+    public $namespace;
+
+    /**
+     * The prefix to be used for the name.
+     *
+     * @var string
+     */
+    public $prefix;
+
+    /**
+     * Declares whether the property definition translates to an attribute instead of an element.
+     *
+     * Default value is false.
+     *
+     * @var bool
+     */
+    public $attribute;
+
+    /**
+     * MAY be used only for an array definition. Signifies whether the array is wrapped
+     * (for example, <books><book/><book/></books>) or unwrapped (<book/><book/>).
+     *
+     * Default value is false. The definition takes effect only when defined alongside
+     * type being array (outside the items).
+     *
+     * @var bool
+     */
+    public $wrapped;
+}