public JavaContainerBuilder setAppRoot(AbsoluteUnixPath appRoot) {
    this.appRoot = appRoot;
    return this;
  }
Sets the app root of the container image (useful for building WAR containers).

@param appRoot the absolute path of the app on the container ({@code /app} by default)
@return this
jib-core/src/main/java/com/google/cloud/tools/jib/api/JavaContainerBuilder.java