def make_figure(plots):
    """
    :param plots: list of pairs (task_name, memory array)
    """
    # NB: matplotlib is imported inside since it is a costly import
    import matplotlib.pyplot as plt

    fig, ax = plt.subplots()
    ax.grid(True)
    ax.set_xlabel('tasks')
    ax.set_ylabel('GB')
    start = 0
    for task_name, mem in plots:
        ax.plot(range(start, start + len(mem)), mem, label=task_name)
        start += len(mem)
    ax.legend()
    return plt
:param plots: list of pairs (task_name, memory array)