code: function(){
                  /*
                   * margin :
                   *    margin_sym S* '{' declaration [ ';' S* declaration? ]* '}' S*
                   *    ;
                   */
                  var tokenStream = this._tokenStream,
                      line,
                      col,
                      marginSym   = this._margin_sym();
  
                  if (marginSym){
                      var node = this.startNode('Margin', tokenStream.curr().range[0], 'body'); //ORION AST generation
                      node.declarations = [];
                      line = tokenStream.token().startLine;
                      col = tokenStream.token().startCol;
  
                      this.fire({
                          type: "startpagemargin",
                          margin: marginSym,
                          line:   line,
                          col:    col
                      });
  
                      this._readDeclarations(true);
  
                      this.fire({
                          type: "endpagemargin",
                          margin: marginSym,
                          line:   line,
                          col:    col
                      });
                      this.endNode(node, tokenStream.curr().range[1]); //ORION AST generation
                      return true;
                  } else {
                      return false;
                  }
              }
docs: CSS3 Paged Media