code: public static boolean equal(Object a, Object b) {
      return com.google.common.base.Objects.equal(a, b);
    }
docs: Determines whether two possibly-null objects are equal. Returns:
  
  <ul>
  <li>{@code true} if {@code a} and {@code b} are both null.
  <li>{@code true} if {@code a} and {@code b} are both non-null and they are equal according to
  {@link Object#equals(Object)}.
  <li>{@code false} in all other situations.
  </ul>
  
  <p>This assumes that any non-null objects passed to this function conform to the {@code
  equals()} contract.