public RegisterSpec withLocalItem(LocalItem local) {
    if ((this.local == local) || ((this.local != null) && this.local.equals(local))) {

      return this;
    }

    return makeLocalOptional(reg, type, local);
  }
Returns an instance that is identical to this one except that the local variable is as
specified in the parameter.

@param local {@code null-ok;} the local item or null for none
@return an appropriate instance
android/android_framework/dex-maker/src/main/java/com/android/dx/rop/code/RegisterSpec.java