protected static SECPSignature readSignature(final RLPInput signedMessage) {
    return signedMessage.readBytes(SignatureAlgorithmFactory.getInstance()::decodeSignature);
  }
Read signature from signed message.

@param signedMessage the signed message
@return the secp signature
consensus/ibft/src/main/java/org/hyperledger/besu/consensus/ibft/payload/PayloadDeserializers.java