@Override
  public void write(Output output, String boundary, String key, Object value)
      throws EncodeException {
    if (value.getClass().isArray()) {
      val objects = (Object[]) value;
      for (val object : objects) {
        parameterWriter.write(output, boundary, key, object);
      }
    } else if (value instanceof Iterable) {
      val iterable = (Iterable<?>) value;
      for (val object : iterable) {
        parameterWriter.write(output, boundary, key, object);
      }
    }
  }
A multiple parameters writer.

@author Artem Labazin
form/src/main/java/feign/form/multipart/ManyParametersWriter.java