public Containerizer setAlwaysCacheBaseImage(boolean alwaysCacheBaseImage) {
    this.alwaysCacheBaseImage = alwaysCacheBaseImage;
    return this;
  }
Controls the optimization which skips downloading base image layers that exist in a target
registry. If the user does not set this property, then read as false.

@param alwaysCacheBaseImage if {@code true}, base image layers are always pulled and cached. If
    {@code false}, base image layers will not be pulled/cached if they already exist on the
    target registry.
@return this
jib-core/src/main/java/com/google/cloud/tools/jib/api/Containerizer.java