anchor.diff:    action-uri       = URL "?" "action=" term
   */
   //TODO action links spec
  +//TODO allow for multiple links per line seperated by ','
   link_header:
     LINK_HEADER  link_path rel (self | link_category)* attributes_attr?
   ;
  
positive.code: URI: ('http://' | 'https://') TOKEN;
  TOKEN: ('a'..'z' | 'A'..'Z') ('a'..'z' | 'A'..'Z')*;
  DIGIT: '0'..'9'+;
  WS: (' ' | '\t'){$channel = HIDDEN};
negative.code:       attributes="occi.storage.size occi.storage.state";
        actions="http://schemas.ogf.org/occi/infrastructure/storage/action#resize ...";
  */
  //TODO allow for multiple categories per line seperated by ','
  category_header:
    CATEGORY_HEADER category_header_val
  ;
  category_header_val:
    term scheme class (title | rel | location | attributes)*
  ;
  term:
    TOKEN
  ;
  