private static boolean equalsHandlesNulls(Object a, Object b) {
    return a == b || (a != null && a.equals(b));
  }
Returns true if a and b are equal or are both null.

@param a null-ok
@param b null-ok
@return Returns true if a and b are equal or are both null
android/android_framework/dex-maker/src/main/java/com/android/dx/ssa/SsaRenamer.java