register binary messenger

commands.cpp

using namespace flutter;

void Commands::registerMessenger(BinaryMessenger* binary_messenger)
{
    std::string channel_name(PACKAGE_NAME);
    channel_name += COMMANDS;

    const StandardMethodCodec& codec = StandardMethodCodec::GetInstance();
    method_channel_ = new MethodChannel<EncodableValue>(binary_messenger, channel_name, &codec);

    method_channel_->SetMethodCallHandler([this](
        const MethodCall<EncodableValue>& call,
        std::unique_ptr<MethodResult<EncodableValue>> result) {
        this->methodChannelHandler(call, result);
    });
}