input: Write a function to create a Linear Regression model that predicts housing prices given the living area and number of rooms. The function should train the model on the provided dataset and return the model object. Include an example usage with test data.
  
  assert train_linear_regression_model(data)==linear_model.LinearRegression(), "The function should return a trained LinearRegression model"
output: def train_linear_regression_model(data):
      from sklearn.linear_model import LinearRegression
      X = data[['living_area', 'rooms']]
      y = data['price']
      model = LinearRegression()
      model.fit(X, y)
      return model