code: def _is_mi_col(x):
      return isinstance(x, str) and x.startswith("__index__")
  
imports: import pandas
  from sktime.datatypes._common import _req
  from sktime.datatypes._common import _ret
label_desc: Use image node_id 1 for calling a global function with example usage: _is_mi_col(x) and returns: unknown