UberClientCall.java

public class UberClientCall<ReqT, RespT> {

  @Nullable private ClientCall<ReqT, RespT> delegate;
  
  public UberClientCall() {}

  public UberClientCall(ClientCall<ReqT, RespT> delegate) {
    this.delegate = delegate;
  }

  public void start(UberNetworkListener<RespT> responseListener, UberNetworkHeaders headers) {
    if (delegate != null) {
      delegate.start(responseListener),
          (Metadata) headers.getNetworkTransportHeaders());
    } else {
      throw new IllegalStateException("Delegate can't be null");
    }
  }

  public void request(int numMessages) {
    if (delegate != null) {
      delegate.request(numMessages);
    } else {
      throw new IllegalStateException("Delegate can't be null");
    }
  }

  public void cancel(@Nullable String message, @Nullable Throwable cause) {
    if (delegate != null) {
      delegate.cancel(message, cause);
    } else {
      throw new IllegalStateException("Delegate can't be null");
    }
  }

  public void halfClose() {
    if (delegate != null) {
      delegate.halfClose();
    } else {
      throw new IllegalStateException("Delegate can't be null");
    }
  }

  public void sendMessage(ReqT message) {
    if (delegate != null) {
      delegate.sendMessage(message);
    } else {
      throw new IllegalStateException("Delegate can't be null");
    }
  }

  public boolean isReady() {
    if (delegate != null) {
      return delegate.isReady();
    } else {
      throw new IllegalStateException("Delegate can't be null");
    }
  }
}