public T mailboxCapacity(int capacity) {
Preconditions.checkArgument(capacity > 0, "mailbox capacity must be >0");
public T mailboxCapacity(int capacity) {
Preconditions.checkArgument(capacity > 0, "mailbox capacity must be >0");
Duration pushTimeout = Duration.create(timeout);
Preconditions.checkArgument(pushTimeout.isFinite(), "invalid value for mailbox push timeout");
Duration pushTimeout = Duration.create(timeout);
Preconditions.checkArgument(pushTimeout.isFinite(), "invalid value for mailbox push timeout");