How to use the indy-sdk.getPairwise function in indy-sdk

exports.sendOffer = async function (theirDid, credentialDefinitionId, credentialData) {
    if(theirDid === '_self_') {
        return issueCredentialToSelf(credentialDefinitionId, credentialData);
    }
    else {
      let credOffer = await sdk.issuerCreateCredentialOffer(await indy.wallet.get(), credentialDefinitionId);
      try {
        credOffer.data = JSON.parse(credentialData);
      } catch (e) {
        credOffer.data = {};
        console.log(e);
      }
      await indy.store.pendingCredentialOffers.write(credOffer);
      let pairwise = await sdk.getPairwise(await indy.wallet.get(), theirDid);
      let myDid = pairwise.my_did;
      let message = await indy.crypto.buildAuthcryptedMessage(myDid, theirDid, MESSAGE_TYPES.OFFER, credOffer);
      let meta = JSON.parse(pairwise.metadata);
      let theirEndpointDid = meta.theirEndpointDid;
      return indy.crypto.sendAnonCryptedMessage(theirEndpointDid, message);
    }
};

exports.getTheirEndpointDid = async function (theirDid) {
    let pairwise = await sdk.getPairwise(await indy.wallet.get(), theirDid);
    let metadata = JSON.parse(pairwise.metadata);
    return metadata.theirEndpointDid;
};

exports.get = async function(theirDid) {
    return await sdk.getPairwise(await indy.wallet.get(), theirDid);
};