String s = a.toUnicodeString();
a.toUnicodeString();
  public static void validateAsTypeDescriptor(VM_Atom a)     throws IllegalArgumentException,           InterruptiblePragma  {    try {      // Atoms are always utf-8.      String s = a.toUnicodeString();    } catch (java.io.UTFDataFormatException udfe) {      IllegalArgumentException iae         = new IllegalArgumentException("The atom in question does not represent a valid UTF8 string, so it's not a type descriptor.");      iae.initCause(udfe);      throw iae;    }  }