def from_der(cls, der):
"""
:param der: A private key previously encoded as DER.
:type der: ``bytes``
:rtype: :class:`~bitsv.PrivateKeyTestnet`
"""
return PrivateKeyTestnet(ECPrivateKey.from_der(der))
def from_der(cls, der, network='main'):
"""
:param der: A private key previously encoded as DER.
:type der: ``bytes``
:param network: 'main', 'test' or 'stn'
:type network: ``str``
:rtype: :class:`~bitsv.PrivateKey`
"""
return PrivateKey(ECPrivateKey.from_der(der), network=network)