input: 
  def create_linear_regression_model(input_dim: int, output_dim: int) -> LinearRegressionModel:
      """ Create a LinearRegressionModel object with specified input and output dimensions.
      The model initializes the weights and biases to zero.
      >>> create_linear_regression_model(3, 1)
      <__main__.LinearRegressionModel object at 0x7f8b1c2b8b50>
      >>> create_linear_regression_model(5, 2)
      <__main__.LinearRegressionModel object at 0x7f8b1c2b8b70>
      """
      return LinearRegressionModel(input_dim, output_dim)
  
output:     class LinearRegressionModel:
          def __init__(self, input_dim, output_dim):
              self.weights = np.zeros((input_dim, output_dim))
              self.biases = np.zeros(output_dim)