> ast.statements[1].stat.rvalue
{ parent: null,
  type: 'num',
  scope: null,
  children: [Getter],
  rawNode: 
   [ { name: 'num',
       start: [Object],
       end: [Object] },
     4 ],
  position: 
   { startToken: 
      { type: 'num',
        value: 4,
        line: 1,
        col: 2,
        pos: 6,
        endpos: 7,
        nlb: false,
        comments_before: [] },
     endToken: 
      { type: 'operator',
        value: '+',
        line: 1,
        col: 1,
        pos: 5,
        endpos: 6,
        nlb: false,
        comments_before: [] } },
  value: 4 }