sign(privatekey, operation, ?:option)

Feature	Add signature to the given hinted object. It is mainly used for sigining operation of multiSig accounts
Parameters	string private key, HintedObject | Operation<Fact>// operation or return value of <operation>.toHintedObject()
Return Value	object signed operation in JSON format

example

// Step1. make operation (example of transfer)
const multiSigAddress = "0x517ffA55D06AaEc6Fa9d27B54e21ebfeb58Ff692fca";
const receiver = "0xdCA5d22F192a5703d629602c25AC7252cE94dBa8fca";
const currencyID = "SIT";
const amount = 50;
const transferOperation = mitum.currency.transfer(multiSigAddress, receiver, currencyID, amount);

// Step2. sign to the operation, Both methods below are valid.

// Usage1 : sign with operation.sign() and add signature using signer.sign()
const privatekey1 = "fa6b1197ec14133d0cbf026b623586ecad79e3ac4c48158e8b06093a3cf7d2c1fpr";
const signedOperation1 = mitum.operation.sign(privatekey1, transferOperation)

const privatekey2 = "4d4c7a3632526575aa5e56c6ee64dc174b67a7edc155ebdb63c333180898f1e6fpr";
const signedOperation2 = mitum.signer.sign(privatekey2, signedOperation1);


// Usage2 : using signer.sign() only
const privatekey1 = "fa6b1197ec14133d0cbf026b623586ecad79e3ac4c48158e8b06093a3cf7d2c1fpr";
const signedOperation1 = mitum.signer.sign(privatekey1, transferOperation)

const privatekey2 = "4d4c7a3632526575aa5e56c6ee64dc174b67a7edc155ebdb63c333180898f1e6fpr";
const signedOperation2 = mitum.signer.sign(privatekey2, signedOperation1);

// Step3. send the signed operation.
// Note that the return value of signer.sign is aready in hintedObject type.
const sendOperation = async () => {
    const res = await mitum.operation.send(signedOperation2);
    console.log(res);
};
sendOperation();