class_docstr: Module level tests for all sktime transformers.
class_docstr_tok: ["Module","level","tests","for","all","sktime","transformers","."]
docstr: Return expected output scitype, given X scitype and input/output.
  
  Parameters
  ----------
  X_scitype : str, scitype of the input to transform
  trafo_input : str, scitype of "instance"
  trafo_output : str, scitype that instance is being transformed to
  
  Returns
  -------
  expected scitype of the output of transform
docstr_tok: ["Return","expected","output","scitype",",","given","X","scitype","and","input\/output",".","Parameters","--","--","--","--","--","X_scitype",":","str",",","scitype","of","the","input","to","transform","trafo_input",":","str",",","scitype","of","``","instance","''","trafo_output",":","str",",","scitype","that","instance","is","being","transformed","to","Returns","--","--","--","-","expected","scitype","of","the","output","of","transform"]
code: def _expected_trafo_output_scitype(
      self, X_scitype, trafo_input, trafo_output
  ):
      """Return expected output scitype, given X scitype and input/output.
  
      Parameters
      ----------
      X_scitype : str, scitype of the input to transform
      trafo_input : str, scitype of "instance"
      trafo_output : str, scitype that instance is being transformed to
  
      Returns
      -------
      expected scitype of the output of transform
      """
      # if series-to-series: input scitype equals output scitype
      if trafo_input == "Series" and trafo_output == "Series":
          return X_scitype
      if trafo_output == "Primitives":
          return "Table"
      if trafo_input == "Series" and trafo_output == "Panel":
          if X_scitype == "Series":
              return "Panel"
          if X_scitype in ["Panel", "Hierarchical"]:
              return "Hierarchical"
      if trafo_input == "Panel" and trafo_output == "Series":
          return "Series"
  
file_path: sktime/sktime/transformations/tests/test_all_transformers.py
imports: import pandas
  from sktime.datatypes import check_is_scitype, convert_to
  from sktime.tests.test_all_estimators import BaseFixtureGenerator, QuickTester
  from sktime.utils._testing.estimator_checks import _assert_array_almost_equal
label_desc: Use image node_id 3 for calling the TestAllTransformers obj's underlying member method code with example usage: obj._expected_trafo_output_scitype(X_scitype, trafo_input, trafo_output) and returns: X_scitype, str, str, str, str