code: def _check_columns(cols):
      if not len(cols):
          raise AssertionError("There must be at least 1 column")
  
      head, tail = cols[0], cols[1:]
  
      N = len(head)
  
      for i, n in enumerate(map(len, tail)):
          if n != N:
              raise AssertionError(
                  "All columns must have the same length: {0}; "
                  "column {1} has length {2}".format(N, i, n)
              )
  
      return N
  
file_path: catboost/contrib/python/pandas/py2/pandas/io/date_converters.py
imports: import numpy
  from pandas._libs.tslibs import parsing
  from pandas.compat import map, range
label_desc: Use image node_id 6 for calling a global function with example usage: _check_columns(cols) and returns: N