private void initialize() {
PreferredProviderHeader header = resource.getSubsystemManifest().getPreferredProviderHeader();
if (header == null)
return;
Collection<PreferredProviderRequirement> requirements = header.toRequirements(resource);
for (PreferredProviderRequirement requirement : requirements)
if (!addSystemRepositoryProviders(requirement))
if (!addLocalRepositoryProviders(requirement))
addRepositoryServiceProviders(requirement);
}