code: def peakmem_read_json_lines_concat(self, index):
      concat(
          read_json(
              self.fname, orient="records", lines=True, chunksize=25000
          )
      )
  
imports: import sys
  import numpy
  from pandas import DataFrame, Index, concat, date_range, json_normalize, read_json, timedelta_range
  from ..pandas_vb_common import BaseIO
  from ..pandas_vb_common import setup
label_desc: Use image node_id 6 for calling the ReadJSONLines obj's underlying member method code with example usage: obj.peakmem_read_json_lines_concat(index) without return types