code: public void bind(ExposedPort exposedPort, Binding binding) {
          if (ports.containsKey(exposedPort)) {
              Binding[] bindings = ports.get(exposedPort);
              ports.put(exposedPort, (Binding[]) ArrayUtils.add(bindings, binding));
          } else {
              if (binding == null) {
                  ports.put(exposedPort, null);
              } else {
                  ports.put(exposedPort, new Binding[] {binding});
              }
          }
      }
docs: Adds a new {@link PortBinding} for the specified {@link ExposedPort} and {@link Binding} to the current bindings.