anchor.diff:  ENV ANDROID_SDK_TOOLS_VERSION="4333796"
   
   # Get the latest version from https://developer.android.com/ndk/downloads/index.html
  -ENV ANDROID_NDK_VERSION="21"
  +ENV ANDROID_NDK_VERSION="r21c"
   
   # nodejs version
   ENV NODE_VERSION="12.x"
  
positive.code:     LANGUAGE="en_US.UTF-8" \
      LC_ALL="en_US.UTF-8"
  
  RUN apt-get clean && apt-get update -qq && apt-get install -qq -y apt-utils locales && locale-gen $LANG
  
  ENV DEBIAN_FRONTEND="noninteractive" \
      TERM=dumb \
  
negative.code:     mkdir --parents "$ANDROID_HOME" && \
      unzip -q sdk-tools.zip -d "$ANDROID_HOME" && \
      rm --force sdk-tools.zip && \
      echo "Installing ndk ${ANDROID_NDK_VERSION}" && \
      wget --quiet --output-document=android-ndk.zip \
      "http://dl.google.com/android/repository/android-ndk-${ANDROID_NDK_VERSION}-linux-x86_64.zip" && \
      mkdir --parents "$ANDROID_NDK_HOME" && \
      unzip -q android-ndk.zip -d "$ANDROID_NDK" && \
      rm --force android-ndk.zip
  