code: public @NotNull S isNotEqualTo(@Nullable A other) {
      failIfEqual(customErrorMessage(), rawDescription(), actual, other);
      return myself();
    }
docs: Verifies that the actual value is not equal to the given one.
  
  @param other the given value to compare the actual value to.
  @return this assertion object.
  @throws AssertionError if the actual value is equal to the given one.