code: from sklearn.base import TransformerMixin
  from sklearn.pipeline import Pipeline
  
  
  class DenseTransformer(TransformerMixin):
  
      def fit(self, X, y=None, **fit_params):
          return self
  
      def transform(self, X, y=None, **fit_params):
          return X.todense()
  
  
  def create_pipeline_with_dense_transformer(
      pipeline_components: list,
      dense_transformer_index: int
  ) -> Pipeline:
  
      dense_transformer = DenseTransformer()
      pipeline_components.insert(dense_transformer_index, ('dense_transformer', dense_transformer))
      return Pipeline(pipeline_components)
  
apis: sklearn.pipeline.Pipeline