code: @Override
    public void setModifiedOn(LocalDateTime modifiedOn) {
      this.modifiedOn = assertNotNull(modifiedOn, () -> "Modified on is required");
      this.lastModifiedOn = defaultIfNull(this.lastModifiedOn, this.modifiedOn);
    }
docs: Sets the date and time when this object was modified.
  
  @param modifiedOn {@link LocalDateTime} capturing the date and time when this object was modified.