code: public WyalFile translate(WyilFile wyilFile) {
  		for (WyilFile.Decl.Unit unit : wyilFile.getModule().getUnits()) {
  			translate(unit);
  		}
  		for (WyilFile.Decl.Unit unit : wyilFile.getModule().getExterns()) {
  			translate(unit);
  		}
  		return wyalFile;
  	}
docs: Translate a WhileyFile into a WyalFile which contains the verification
  conditions necessary to establish that all functions and methods in the
  WhileyFile meet their specifications, and that no array-out-of-bounds or
  division-by-zero exceptions are possible (amongst other things).
  
  @param wyilFile
  The input file to be translated
  @return