## Augment

### Description

Modify an existing reference by adding nested elements or (re-)assigning properties mapped as XML attributes. This is an unusual task that makes use of Ant's internal processing mechanisms to reload a previously declared reference by means of the 'id' attribute, then treats the declared `augment` element as though it were the original element. Since Apache Ant 1.8.1

### Parameters

Attribute | Description | Required
id | The id of the reference to augment. If no such reference has been declared a `BuildException` is generated. | Yes

Additional permissible attributes are dependent on the reference to be modified.

### Parameters specified as nested elements

Permissible nested elements are dependent on the reference to be modified.

### Examples

Given

      <fileset id="input-fs" dir="${basedir}" />

      <augment id="input-fs" excludes="foo" />

Modifies the `excludes` attribute of `input-fs`.

      <augment id="input-fs">
        <filename name="bar" />
      </augment>

Adds a `filename` selector to `input-fs`.