def METHOD_NAME (self, Buffer):
    if len (Buffer) < self._StructSize:
        raise ValueError
    (MonotonicCount, dwLength, wRevision, wCertificateType, CertType) = \
        struct.unpack (
                 self._StructFormat,
                 Buffer[0:self._StructSize]
                 )
    if dwLength < self._StructAuthInfoSize:
        raise ValueError
    if wRevision != self._WIN_CERT_REVISION:
        raise ValueError
    if wCertificateType != self._WIN_CERT_TYPE_EFI_GUID:
        raise ValueError
    if CertType != self._EFI_CERT_TYPE_PKCS7_GUID.bytes_le:
        raise ValueError
    self.MonotonicCount   = MonotonicCount
    self.dwLength         = dwLength
    self.wRevision        = wRevision
    self.wCertificateType = wCertificateType
    self.CertType         = uuid.UUID (bytes_le = CertType)
    self.CertData         = Buffer[self._StructSize:self._MonotonicCountSize + self.dwLength]
    self.Payload          = Buffer[self._MonotonicCountSize + self.dwLength:]
    self._Valid           = True
    return self.Payload