How to use the stellar-base.Keypair function in stellar-base

  .attr("id", () => stellar.Keypair.random().publicKey())
  .attr("balance", "19729999500")

  .attr("signer", () => stellar.Keypair.random().publicKey())
  .attr("weight", () => Math.floor(Math.random() * 5));

  .attr("accountID", () => stellar.Keypair.random().publicKey())
  .attr("signer", () => stellar.Keypair.random().publicKey())

  .attr("id", () => stellar.Keypair.random().publicKey())
  .attr("balance", "19729999500")

module.exports.newAddressFromPublicKey = function(publicKeyString) {
  var publicKeyBytes = new Buffer(publicKeyString, "base64");
  var keyPair = new StellarBase.Keypair({publicKey: publicKeyBytes});
  return keyPair.publicKey();
};