def load_pem_x509_certificates(data: bytes) -> List[x509.Certificate]:
    """
    Load a chain of PEM-encoded X509 certificates.
    """
    boundary = b"-----END CERTIFICATE-----\n"
    certificates = []
    for chunk in data.split(boundary):
        if chunk:
            certificates.append(x509.load_pem_x509_certificate(chunk + boundary))
    return certificates

    Load a chain of PEM-encoded X509 certificates.
    
src/aioquic/tls.py