docs: function hash(input, algo, type){
      // string or buffer input ? => keep it
      if (typeof input !== 'string' && !(input instanceof Buffer)){
          input = JSON.stringify(input);
      }
  
      // create hash algo
      var sum = _crypto.createHash(algo);
  
      // set content
      sum.update(input);
  
      // binary output ?
      if (type && type.toLowerCase().trim() == 'binary'){
          // calculate hashsum
          return sum.digest();
  
      // base 64 urlsafe ?
      }else if (type==='base64-urlsafe'){
          return base64urlsafe(sum.digest('base64'));
  
      // string output
      }else{
          // calculate hashsum
          return sum.digest(type);
      }
  }