class_docstr: Base pairwise transformer for panel data template class.
  
  The base pairwise transformer specifies the methods and method signatures that all
  pairwise transformers have to implement.
  
  Specific implementations of these methods is deferred to concrete classes.
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docstr: Compute distance/kernel matrix.
  
  private _transform containing core logic, called from transform
  
  Behaviour: returns pairwise distance/kernel matrix
      between samples in X and X2 (equal to X if not passed)
  
  Parameters
  ----------
  X : guaranteed to be Series or Panel of mtype X_inner_mtype, n instances
      if X_inner_mtype is list, _transform must support all types in it
      Data to be transformed
  X2 : guaranteed to be Series or Panel of mtype X_inner_mtype, m instances
      if X_inner_mtype is list, _transform must support all types in it
      Data to be transformed
      default X2 = X
  
  Returns
  -------
  distmat: np.array of shape [n, m]
      (i,j)-th entry contains distance/kernel between X[i] and X2[j]
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code: def _transform(self, X, X2=None):
      """Compute distance/kernel matrix.
  
      private _transform containing core logic, called from transform
  
      Behaviour: returns pairwise distance/kernel matrix
          between samples in X and X2 (equal to X if not passed)
  
      Parameters
      ----------
      X : guaranteed to be Series or Panel of mtype X_inner_mtype, n instances
          if X_inner_mtype is list, _transform must support all types in it
          Data to be transformed
      X2 : guaranteed to be Series or Panel of mtype X_inner_mtype, m instances
          if X_inner_mtype is list, _transform must support all types in it
          Data to be transformed
          default X2 = X
  
      Returns
      -------
      distmat: np.array of shape [n, m]
          (i,j)-th entry contains distance/kernel between X[i] and X2[j]
      """
      raise NotImplementedError
  
imports: from sktime.base import BaseEstimator
  from sktime.datatypes import check_is_scitype, convert_to
  from sktime.datatypes._series_as_panel import convert_Series_to_Panel
label_desc: Use image node_id 8 for calling the BasePairwiseTransformerPanel obj's underlying member method code with example usage: obj._transform(X, X2) without return types