class_docstr: A subset of the cartesian product of cases have special motivations:
  
  "nans" x "nans"
      if nan-objects are different objects,
      this has the potential to trigger O(n^2) running time
  
  "short" x "long"
      running time dominated by the preprocessing
  
  "long" x "short"
      running time dominated by look-up
  
  "long" x "long"
      no dominating part
  
  "long_floats" x "long_floats"
      because of nans floats are special
      no dominating part
code: def time_isin(self, series_type, vals_type):
      self.series.isin(self.values)
  
imports: import numpy
  from pandas import Categorical, Index, NaT, Series, date_range
label_desc: Use image node_id 2 for calling the IsInForObjects obj's underlying member method code with example usage: obj.time_isin(series_type, vals_type) without return types