def dependencies(package_json, version_number=None):
    '''Get the list of package names of dependencies for a package.'''
    versions = package_json['versions']
    if version_number is None:
        # Get the maximum version number if the caller didn't provide one explicity.
        version_number = sorted(versions, cmp=compare_version_numbers, reverse=True)[0]
    try:
        return package_json['versions'][version_number]['dependencies'].keys()
    except __HOLE__:
        return None
dataset/ETHPy150Open zsck/npm-to-git/n2g.py/dependencies