public TypedConstant getConstantValue() {
    return constantValue;
  }
Gets the constant value of this instance. The returned value is an instance of one of: {@code
CstString}, {@code CstInteger}, {@code CstLong}, {@code CstFloat}, or {@code CstDouble}.

@return {@code non-null;} the constant value
android/android_framework/dex-maker/src/main/java/com/android/dx/cf/attrib/AttConstantValue.java