def METHOD_NAME(podspec_data):
    """
    Return a Package object from a package data mapping or None.
    """
    name = podspec_data.get('name')
    version = podspec_data.get('version')
    declared_license = podspec_data.get('license')
    summary = podspec_data.get('summary', '')
    description = podspec_data.get('description', '')
    homepage_url = podspec_data.get('homepage_url')
    source = podspec_data.get('source')
    authors = podspec_data.get('author') or []
    if summary and not description.startswith(summary):
        desc = [summary]
        if description:
            desc += [description]
        description = '\n'.join(desc)
    author_names = []
    author_email = []
    if authors:
        for split_author in authors:
            split_author = split_author.strip()
            author, email = parse_person(split_author)
            author_names.append(author)
            author_email.append(email)
    parties = list(party_mapper(author_names, author_email))
    package = CocoapodsPackage(
        name=name,
        version=version,
        vcs_url=source,
        source_packages=list(source.split('\n')),
        description=description,
        declared_license=declared_license,
        homepage_url=homepage_url,
        parties=parties
    )
    return package