Return a new |CorePropertiesPart| object initialized with default
        values for its base properties.

def default(cls, package):
        """
        Return a new |CorePropertiesPart| object initialized with default
        values for its base properties.
        """
        core_properties_part = cls._new(package)
        core_properties = core_properties_part.core_properties
        core_properties.title = 'Word Document'
        core_properties.last_modified_by = 'python-docx'
        core_properties.revision = 1
        core_properties.modified = datetime.utcnow()
        return core_properties_part