code: public void setDoc(boolean doc) {
          checkRpmFileSetAttributesAllowed();
          if(doc) {
              directive.set(Directive.RPMFILE_DOC);
          } else {
              directive.unset(Directive.RPMFILE_DOC);
          }
      }
docs: Supports RPM's {@code %doc} directive, which flags the files as being documentation.  RPM keeps track of
  documentation files in its database, so that a user can easily find information about an installed package.
  Permitted values for this directive are:
  <ul>
  <li> {@code true}    (equivalent to specifying {@code %doc}
  <li> {@code false}     (equivalent to omitting {@code %doc})
  </ul>
  
  @see <a href="http://www.rpm.org/max-rpm-snapshot/s1-rpm-inside-files-list-directives.html">rpm.com</a>
  @see #directive
  
  @param doc to set