def _delete_reference_to_id(id)
      _all_attributes.each do |attr|
        ivar = ('@' + attr.to_s).to_sym
        value = instance_variable_get(ivar)
        if value && value.respond_to?(:is_poxreference?) && value.id == id
          instance_variable_set(ivar, nil)
        end
      end
      mark_as_modified
    end
def _delete_reference_to_id(id)
      _all_attributes.each do |attr|
        ivar = ('@' + attr.to_s).to_sym
        value = instance_variable_get(ivar)
        if value && value.respond_to?(:is_poxreference?) && value.id == id
          instance_variable_set(ivar, nil)
        end
      end
      mark_as_modified
    end
This method should only be used during store repair operations. It will
 delete all references to the given object ID.
 @param id [Integer] targeted object ID