def build_includes(include_packages, freezer=None, optional=None):
freezer = resolve_freezer(freezer)<EOL>package_references = _import_packages(include_packages, optional=optional)<EOL>includes = freezer.build_includes(package_references)<EOL>return includes<EOL>
Iterate the list of packages to build a complete list of those packages as well as all subpackages.

:param include_packages: list of package names
:type: include_pacakges: list of basestr
:param freezer: The freezer to use (See FREEZER constants)
:param optional: Optional pacakge names to include (will only issue a warning if they don't exist)
:return: complete set of package includes