code: public static <T> MutatorResult<T> of(final T result, final int mutations) {
  		return new MutatorResult<>(result, mutations);
  	}
docs: Create a new mutation result with the given values.
  
  @param result the mutation result
  @param mutations the number of mutations
  @param <T> the mutation result type
  @return a new mutation result
  @throws IllegalArgumentException if the given {@code mutations} is
  negative
  @throws NullPointerException if the given mutation result is {@code null}