Retrieving a public key

		GetPublicKey.Done done = new GetPublicKey.Done() {
			void onGetPublicKeyDone(@NonNull PublicKey publicKey) {
				// The object was found, and the public key was parsed
			}

			void onGetPublicKeyInvalid(@NonNull String reason) {
				// The object was not found, or not a valid public key
			}

			void onGetPublicKeyFailed(@NonNull String error) {
				// The store reported an error
			}
		};

		new GetPublicKey(hash, store, keyPair, done);

		var done = keyPair.getPublicKey(hash, store);

		done.onDone = function(publicKey) {
			// The object was found, and the public key was parsed
		};

		done.onInvalid = function(reason) {
			// The object was not found, or not a valid public key
		};

		done.onFailed = function(error) {
			// The store reported an error
		};

		my ($publicKey, $invalidReason, $storeError) = $keyPair->getPublicKey($hash, $store);

		if (defined $storeError) {
			# The store reported an error
		} elsif (defined $invalidReason) {
			# The object was not found, or not a valid public key
		} else {
			# The object was found, and the public key was parsed
		}

Retrieves a public key object from a store, and parses its public key.

If the store reported an error, the operation fails with that error. It may succeed when called again at a later time.

If the object is not found, or does not contain a public key, the operation fails as invalid.