input: from typing import Any
  
  def generate_ml_model(dataset: Any, model_type: str) -> Any:
      """ Generates a machine learning model using the given dataset and model type.
      The function supports the MNIST dataset and the model type 'LogisticRegression'.
      >>> generate_ml_model('mnist_784', 'LogisticRegression')
      LogisticRegression()
      """
output:     from sklearn.datasets import fetch_openml
      from sklearn.linear_model import LogisticRegression
  
      if dataset == 'mnist_784' and model_type == 'LogisticRegression':
          mnist = fetch_openml('mnist_784', version=1)
          model = LogisticRegression()
          return model