How to use the crypto-ld.Ed25519KeyPair.generate function in crypto-ld

async function _generateDid() {
  const mockDoc = jsonld.util.clone(mockData.privateDidDocuments.alpha);
  const capabilityInvocationKey = await Ed25519KeyPair.generate();
  const keyFingerprint = `z${capabilityInvocationKey.fingerprint()}`;

  const did = `did:v1:test:nym:${keyFingerprint}`;
  // cryptonym dids are based on fingerprint of capabilityInvokation key
  mockDoc.id = did;
  capabilityInvocationKey.id = _generateKeyId(
    {did, key: capabilityInvocationKey});
  const controller = did;
  capabilityInvocationKey.controller = controller;
  mockDoc.capabilityInvocation[0] = {
    id: capabilityInvocationKey.id,
    type: capabilityInvocationKey.type,
    controller: capabilityInvocationKey.controller,
    publicKeyBase58: capabilityInvocationKey.publicKeyBase58
  };
  const authenticationKey = await Ed25519KeyPair.generate();

const keyFingerprint = `z${capabilityInvocationKey.fingerprint()}`;

  const did = `did:v1:test:nym:${keyFingerprint}`;
  // cryptonym dids are based on fingerprint of capabilityInvokation key
  mockDoc.id = did;
  capabilityInvocationKey.id = _generateKeyId(
    {did, key: capabilityInvocationKey});
  const controller = did;
  capabilityInvocationKey.controller = controller;
  mockDoc.capabilityInvocation[0] = {
    id: capabilityInvocationKey.id,
    type: capabilityInvocationKey.type,
    controller: capabilityInvocationKey.controller,
    publicKeyBase58: capabilityInvocationKey.publicKeyBase58
  };
  const authenticationKey = await Ed25519KeyPair.generate();
  authenticationKey.id = _generateKeyId(
    {did, key: authenticationKey});
  authenticationKey.controller = controller;
  mockDoc.authentication[0] = {
    id: authenticationKey.id,
    type: authenticationKey.type,
    controller: authenticationKey.controller,
    publicKeyBase58: authenticationKey.publicKeyBase58
  };
  const documentLoader = await _createDidDocumentLoader({record: mockDoc});
  return {
    authenticationKey, did, documentLoader, mockDoc, capabilityInvocationKey
  };
}

const createEd25519Keys = async () => {
  const key = await Ed25519KeyPair.generate();
  return key;
};