You can programmatically construct a PharIo\Manifest\Manifest object by instantiating its required components: ApplicationName, Version, Manifest type (e.g., Library), CopyrightInformation, RequirementCollection, and BundledComponentCollection.
$bundled = new \PharIo\Manifest\BundledComponentCollection();
$bundled->add(
new \PharIo\Manifest\BundledComponent('vendor/packageA', new \PharIo\Version\Version('1.2.3-dev')
)
);
$manifest = new PharIo\Manifest\Manifest(
new \PharIo\Manifest\ApplicationName('vendor/package'),
new \PharIo\Version\Version('1.0.0'),
new \PharIo\Manifest\Library(),
new \PharIo\Manifest\CopyrightInformation(
new \PharIo\Manifest\AuthorCollection(),
new \PharIo\Manifest\License(
'BSD-3-Clause',
new \PharIo\Manifest\Url('https://spdx.org/licenses/BSD-3-Clause.html')
)
),
new \PharIo\Manifest\RequirementCollection(),
$bundled
);
echo (new ManifestSerializer)->serializeToString($manifest);