code: function(len){
      var chunk = len[0];
      len = chunk ? chunk.length : len;
      this.str = this.str.substr(len);
      if (chunk) {
        this.move(chunk);
      } else {
        this.column += len;
      }
    }
docs: Consume the given `len`.
  
  @param {Number|Array} len
  @api private