docs(example): showcase LicenseChoiceFactory (#428)

Signed-off-by: Jan Kowalleck <jan.kowalleck@gmail.com>

examples/build_and_serialize.py

@@ -1,39 +1,46 @@
-from cyclonedx.factory.license import LicenseFactory
-from cyclonedx.model import LicenseChoice, OrganizationalEntity, XsUri
+from cyclonedx.factory.license import LicenseChoiceFactory, LicenseFactory
+from cyclonedx.model import OrganizationalEntity, XsUri
 from cyclonedx.model.bom import Bom
 from cyclonedx.model.component import Component, ComponentType
 from cyclonedx.output.json import JsonV1Dot4
 from cyclonedx.output.xml import XmlV1Dot4
 from packageurl import PackageURL
 
-lFac = LicenseFactory()
+lc_factory = LicenseChoiceFactory(license_factory=LicenseFactory())
 
 # region build the BOM
 
 bom = Bom()
 bom.metadata.component = rootComponent = Component(
     name='myApp',
     type=ComponentType.APPLICATION,
-    licenses=[LicenseChoice(license=lFac.make_from_string('MIT'))],
+    licenses=[lc_factory.make_from_string('MIT')],
     bom_ref='myApp',
 )
 
-component = Component(
+component1 = Component(
     type=ComponentType.LIBRARY,
     name='some-component',
     group='acme',
     version='1.33.7-beta.1',
-    licenses=[LicenseChoice(license=lFac.make_from_string('(c) 2021 Acme inc.'))],
+    licenses=[lc_factory.make_from_string('(c) 2021 Acme inc.')],
     supplier=OrganizationalEntity(
         name='Acme Inc',
         urls=[XsUri('https://www.acme.org')]
     ),
     bom_ref='myComponent@1.33.7-beta.1',
     purl=PackageURL('generic', 'acme', 'some-component', '1.33.7-beta.1')
 )
+bom.components.add(component1)
+bom.register_dependency(rootComponent, [component1])
 
-bom.components.add(component)
-bom.register_dependency(rootComponent, [component])
+component2 = Component(
+    type=ComponentType.LIBRARY,
+    name='some-library',
+    licenses=[lc_factory.make_from_string('GPL-3.0-only WITH Classpath-exception-2.0')]
+)
+bom.components.add(component2)
+bom.register_dependency(component1, [component2])
 
 # endregion build the BOM