private static boolean equalsHandlesNulls(LocalItem a, LocalItem b) {
    return (a == b) || ((a != null) && a.equals(b));
  }
Returns true if a and b are equal, whether or not either of them are null.

@param a
@param b
@return true if equal
android/android_framework/dex-maker/src/main/java/com/android/dx/ssa/PhiTypeResolver.java