public final int getLiteralNibble() {
    if ((literal < -8) || (literal > 7)) {
      throw new DexException("Literal out of range: " + Hex.u8(literal));
    }

    return (int) literal & 0xf;
  }
Gets the literal value, masked to be a nibble in size. This will throw if the value is out of
the range of a signed nibble.
android/android_framework/dex-maker/src/main/java/com/android/dx/io/instructions/DecodedInstruction.java