from typing import List


def train_test_split_data(text: List[str], test_size=0.2):
    """ Splits the input corpus in a train and a test set
    :param text: input corpus
    :param test_size: size of the test set, in fractions of the original corpus
    :return: train and test set
    """
    k = int(len(text) * (1 - test_size))
    return text[:k], text[k:]