private static void internInitial(CstType cst) {
    if (interns.putIfAbsent(cst.getClassType(), cst) != null) {
      throw new IllegalStateException("Attempted re-init of " + cst);
    }
  }
Constructs an instance.

@param type {@code non-null;} the underlying type
android/android_framework/dex-maker/src/main/java/com/android/dx/rop/cst/CstType.java