def fibonacci_sequence(n: int) -> str:
    """
    Generate the first n terms of the Fibonacci sequence.
    The sequence begins with 0, 1. Each later term is the sum of the
    previous two; use a loop to generate those terms.

    Parameters
    ----------
    n : int
        The nonnegative number of terms in the Fibonacci sequence to generate.

    Returns
    -------
    str
        The terms separated by a comma and one space, or an empty string
        when n is 0.

    Examples
    --------
    >>> fibonacci_sequence(5)
    '0, 1, 1, 2, 3'
    >>> fibonacci_sequence(10)
    '0, 1, 1, 2, 3, 5, 8, 13, 21, 34'
    >>> fibonacci_sequence(0)
    ''
    >>> fibonacci_sequence(1)
    '0'
    """
    raise NotImplementedError("Replace this line with your code.")