code: @Override
    @SuppressWarnings("unchecked")
    public void setModifiedBy(USER modifiedBy) {
      this.modifiedBy = assertNotNull(modifiedBy, () -> "Modified by is required");
      this.lastModifiedBy = defaultIfNull(this.lastModifiedBy, this.modifiedBy);
    }
docs: Sets the user responsible for modifying this object.
  
  @param modifiedBy object representing the user responsible for modifying this object.