@Override
  public int hashCode() {
    int result = 17;
    result = 31 * result + declaringType.hashCode();
    result = 31 * result + name.hashCode();
    result = 31 * result + parameters.hashCode();
    result = 31 * result + returnType.hashCode();
    return result;
  }
Returns a descriptor like "(Ljava/lang/Class;[I)Ljava/lang/Object;".
android/android_framework/dex-maker/src/main/java/com/android/dx/MethodId.java