code: public void consolidate() {
  		Decl.Module module = target.getModule();
  		for(ExternalGroup group : consolidations) {
  			// TODO: this could be made way more efficient by collecting all consolidate
  			// units into one batch
  			module.putExtern(group.consolidate());
  		}
  		consolidations.clear();
  	}
docs: Consolidate the status of external symbols. For example, this will ensure all
  external units which have imported symbols are made available. Likewise, it
  may garbage collect available symbols and units which are no longer required.
  
  @return