code: private static boolean isEqualOrNull(String left, String right) {
          return (left != null && left.equals(right)) || (left == null && right == null);
      }
docs: Compares two strings for equality; if both strings are null they are
  considered equal.
  
  @param left the first string to compare
  @param right the second string to compare
  @return true if the strings are equal or if they are both null; otherwise
  false.