code: def mkts(series, length, dtstart="1911-11-01", ff="D"):
      return pd.DataFrame(
          {c: np.random.random(length) for c in series},
          index=pd.date_range(dtstart, freq=ff, periods=length),
      )
  
file_path: tslumen/tests/unit/report/util.py
imports: import datetime
  import copy
  import numpy
  import pandas
  from tslumen.profile.base import BundledResult, BundledResultDetails
  from tslumen.profile.stat_tests import TestResult
label_desc: Use image node_id 1 for calling a global function with example usage: mkts(series, length, dtstart, ff) and returns: pd